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Inorganic powder analysis by time-wavelength resolved luminescence spectroscopy Paski, Edgar Francis 1988

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INORGANIC POWDER ANALYSIS BY TIME-WAVELENGTH RESOLVED LUMINESCENCE SPECTROSCOPY By EDGAR FRANCIS PASKI B.Sc, University of Waterloo, 1981 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n THE FACULTY OF GRADUATE STUDIES Department of Chemistry We accept t h i s thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA September 1988 © Edgar Francis Paski, 1988 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department The University of British Columbia Vancouver, Canada Date DE-6 (2/88) ABSTRACT An investigation into the potential of time-wavelength r e s o l v e d luminescence spectroscopy f o r the a n a l y s i s of inorganic powders was performed. A time-wavelength resolved luminescence spectrometer c o n s i s t i n g of an excimer l a s e r , scanning monochromator, and gated integrator was construc-ted. The spectrometer had wavelength coverage from 265 nm to 800 nm, i t was capable of measuring l i f e t i m e s between 100 ns and 500 ms. Sample excitation was done at 193 nm and 248 nm. A luminescence system model of f i r s t order decay i n the time domain and a Gaussian f u n c t i o n f o r the emission band was assumed. The time-wavelength r e s o l v e d luminescence spectrum was de s c r i b e d by the parameters: l i f e t i m e , peak maxima, peak h a l f w i d t h , and i n t e n s i t y f a c t o r . Parameter e s t i m a t i o n was done with an al g o r i t h m employing a l i n e a r algebra construct and simplex optimization. The algorithm's performance on highly overlapped spectra was evaluated. For two component mixtures having a 1 % RSD noise l e v e l , overlaps gre a t e r than 0.3 h a l f w i d t h s i n the s p e c t r a l domain and l i f e t i m e r a t i o s g r e a t e r than 1:1.3 were r e s o l v e d with a l l parameter estimates having an error of less than ±2%. The luminescence spect r a of CaMo0 4, SrMo04, BaMo04, ZnMoC-4, CdMo04, PbMoC<4, CaWG-4, SrW04, BaWC>4, ZnWC>4, CdW04* and PbWC>4 c o n s i s t e d of broad f e a t u r e l e s s bands showing simple exponential decay. Mixed c r y s t a l s of Ca(MoxW-| _ x)°4 and Sr(Mo x w-| _ x)04 were examined. Tungstate emission was i i quenched by molybdate, the molybdate emission dominated when x was g r e a t e r than 0.15. The tungstate l i f e t i m e was found to be proportional to molybdate concentration. The luminescence spect r a of CaZrG^, SrZrC«3, BaZr03» CaHf0 3 f SrHfC>3, BaHf03, CaO, SrO, and BaO as pure compounds and doped with T l , Pb, Sb, and B i were studied. The pure zirconates and hafnates showed short l i v e d (<100 ns) lumi-nescence with 248 not e x c i t a t i o n ; no r e a d i l y d i s c e r n i b l e luminescence was observed with 1 93 nm e x c i t a t i o n . Doped compounds tended to show luminescence c h a r a c t e r i s t i c of the dopant ion. i i i T A B L E OF CONTENTS P a g e A b s t r a c t i i T a b l e o f c o n t e n t s i v L i s t o f t a b l e s v i i L i s t o f f i g u r e s v i i i A c k n o w l e d g e m e n t s x v i i C h a p t e r 1: INTRODUCTION 1 1.1 O v e r v i e w 1 1 .2 H i s t o r i c a l 1 1.2.1 T h e B o l o g n a s t o n e 3 1 . 2 . 2 C o n t r i b u t i o n s o f B e c q u e r e l a n d S t o k e s 5 1 .3 L u m i n e s c e n c e o f a n i s o l a t e d a t o m 6 1 .3 .1 E i n s t e i n t h e o r y o f r a d i a t i o n 7 1.3.2 N a t u r a l l i n e b r o a d e n i n g 9 1.4 L u m i n e s c e n c e o f a t o m s i n a g a s 10 1.4.1 S p e c t r a l l i n e b r o a d e n i n g e f f e c t s 11 1.4.2 Q u a n t u m y i e l d s a n d e x c i t e d s t a t e l i f e t i m e s 13 1 .5 G a s p h a s e m o l e c u l a r l u m i n e s c e n c e 14 1.6 L u m i n e s c e n c e i n t h e s o l i d s t a t e 18 1.6.1 E x c i t a t i o n m e t h o d s 18 1 . 6 . 2 M o l e c u l a r s o l i d s 21 1.6.3 S e m i c o n d u c t o r s 22 1 . 6 . 4 I n o r g a n i c i n s u l a t o r s 25 1.6.4.1 T h e c o l o r c e n t e r i n a l k a l i h a l i d e s 26 1 . 6 . 4 . 2 T r i v a l e n t r a r e e a r t h i o n s i n l a n t h a n u m c h l o r i d e 27 1 . 6 . 5 T h e c o n f i g u r a t i o n c o o r d i n a t e m o d e l 29 i v 1.6.6 Energy transfer 32 1.6.7 Energy migration 38 1.7 Luminescence i n a n a l y t i c a l chemistry 41 Chapter 2: EXPERIMENTAL 44 2.1 Overview 44 2.2 Spectrometer 44 2.2.1 Computer system 44 2.2.2 Software 44 2.2.3 E x c i t a t i o n source 46 2.2.4 Laser pulse energy monitor 47 2.2.5 Sample holders 51 2.2.6 Spectrometer optics 53 2.2.7 Wavelength scanning 53 2.2.8 Detector 55 2.2.9 Sign a l a c q u i s i t i o n 55 2.2.10 Spectral response correction 56 2.2.11 Cabling 56 2.2.12 E l e c t r i c a l power 58 2.2.13 Electromagnetic interference 58 2.3 Compound preparation 63 2.3.1 Molybdates and tungstates 63 2.3.2 Zirconates and hafnates 65 2.4 Compound analysis 66 Chapter 3: DATA REDUCTION 71 3.1 Overview 71 3.2 System model 71 v 3.3 Optimization and parameter estimation 73 3.3.1 Simplex optimization 74 3.3.2 The Kalman f i l t e r 77 3.4 The data reduction algorithm 79 3.5 Computers and FORTRAN compilers used 80 3.6 Algorithm evaluation 81 3.6.1 Performance on two component mixtures 81 3.6.2 Performance on three component mixtures 93 Chapter 4: Inorganic powders 100 4.1 Overview 100 4.2 Molybdates and tungstates 100 4.3 Zirconates and hafnates 115 Chapter 5: CONCLUDING REMARKS 156 References 160 Appendix 1: Spectrometer control program i n BASIC 168 Appendix 2: Monochromator stepper motor driver routine 174 Appendix 3: Luminescence data f i l e handler i n BASIC 175 Appendix 4: Data reduction program using simplex optimization 182 v i L I S T OF T A B L E S T a b l e D e s c r i p t i o n P a g e I R e a g e n t s 64 I I X - r a y p o w d e r d i f f r a c t i o n d a t a f o r a l k a l i n e e a r t h z i r c o n a t e s a n d h a f n a t e s . 68 I I I E x p e c t e d a n d m e a s u r e d c o m p o s i t i o n o f m o l y b d a t e a n d t u n g s t a t e s a l t s p r e p a r e d . 70 I V P a r a m e t e r a s s i g n m e n t s f o r t w o c o m p o n e n t m i x t u r e s . 83 V C o m p a r i s o n o f a c t u a l a n d e s t i m a t e d p a r a m e t e r s f o r t h r e e c o m p o n e n t m i x t u r e s . 95 V I S p e c t r a l p a r a m e t e r s f o r t u n g s t a t e a n d m o l y b d a t e s a l t s . 109 v i i L I S T OF F I G U R E S F i g u r e D e s c r i p t i o n P a g e 1.1 L u m i n e s c e n c e p r o c e s s e s i n a t o m s : ( A ) r e s o n a n c e f l u o r e s c e n c e , ( B ) d i r e c t l i n e f l u o r e s c e n c e , ( C ) t h e r m a l l y a s s i s t e d d i r e c t l i n e f l u o r e s c e n c e , (D) t h e r m a l l y a s s i s t e d r e s o n a n c e f l u o r e s c e n c e , ( E ) s t e p w i s e l i n e f l u o r e s c e n c e , ( F ) t h e r m a l l y a s s i s t e d s t e p w i s e l i n e f l u o r e s c e n c e . 8 1 .2 L u m i n e s c e n c e p r o c e s s e s i n i r - e l e c t r o n s y s t e m s . 16 1 .3 L u m i n e s c e n c e a s s o c i a t e d e l e c t r o n - h o l e p a i r r e c o m b i -n a t i o n p r o c e s s e s i n s e m i c o n d u c t o r s . 24 1 .4 C o n f i g u r a t i o n c o o r d i n a t e d i a g r a m f o r t r a n s i t i o n s b e t w e e n a n e x c i t e d s t a t e a n d t h e g r o u n d s t a t e . 30 1 .5 N o n r a d i a t i v e e n e r g y m o v e m e n t i n s o l i d s : ( a ) e n e r g y t r a n s f e r , ( b ) e n e r g y m i g r a t i o n , ( c ) c o n c e n t r a t i o n q u e n c h i n g w i t h t r a n s f e r t o k i l l e r s i t e s , ( d ) t r a p s a n d d e l a y e d l u m i n e s c e n c e . 33 2 . 1 B l o c k d i a g r a m o f t h e t i m e - w a v e l e n g t h r e s o l v e d l u m i -n e s c e n c e s p e c t r o m e t e r . 45 2 . 2 E x c i m e r l a s e r p o w e r o u t p u t f l u c t u a t i o n s , t i m e s c a l e i s s h o t n u m b e r T 1 0 ; a t 3 H z : ( A ) f r e s h f i l l g a s , ( B ) s a m e f i l l g a s t h r e e h o u r s l a t e r . 48 2 . 3 M o d i f i c a t i o n t o l a s e r t h y r a t r o n c i r c u i t . 4 9 2 . 4 R e f e r e n c e P M T h o u s i n g . 50 2 . 5 P e a k d e t e c t o r c i r c u i t d i a g r a m . 52 2 . 6 S p e c t r o m e t e r o p t i c a l d i a g r a m . 54 2 . 7 P h o t o d i o d e t r i g g e r h o u s i n g a n d c i r c u i t d i a g r a m . 57 2 . 8 P o w e r l i n e v o l t a g e f l u c t u a t i o n s . 5 9 2 . 9 E M I f r o m e x c i m e r l a s e r ; r e g i o n P - b e f o r e l a s e r p u l s e , r e g i o n T - d u r i n g p u l s e , r e g i o n F - a f t e r l a s e r p u l s e : ( A ) 1 .0 m s i g n a l c a b l e l e n g t h , ( B ) 2 . 0 s i g n a l c a b l e l e n g t h . 62 3 .1 T w o d i m e n s i o n a l s i m p l e x i l l u s t r a t i n g r e f l e c t i o n , e x p a n s i o n , a n d c o n t r a c t i o n o p e r a t i o n s . 76 v i i i F i g u r e D e s c r i p t i o n P a g e 3 . 2 M a x i m u m e r r o r i n e s t i m a t e d p a r a m e t e r s f o r b o t h c o m p o n e n t s A a n d B a s a f u n c t i o n o f p e a k s e p a r a t i o n i n b o t h t i m e a n d w a v e l e n g t h d o m a i n s . S y n t h e t i c d a t a w i t h : 1 % R S D n o i s e , c o m p o n e n t B i n t e n s i t y = 1 0 , o t h e r p a r a m e t e r s a s i n T a b l e I . G u e s s v a l u e s u s e d : A = 1 2 . 3 u s , B = 123 u s . 84 3 . 3 S y n t h e t i c s p e c t r a w i t h 1 % R S D n o i s e a d d e d , v e r t i c a l a x i s : i n t e n s i t y . ( a ) L i f e t i m e s : A = 1 0 u s , B = 2 5 y s ; p e a k m a x i m a : A = 435 n m , B = 465 n m . (b) L i f e t i m e s : A = 10 u s , B = 1 u s ; p e a k m a x i m a : A = 435 n m , B = 71 4 n m . 86 3 . 4 M a x i m u m e r r o r i n e s t i m a t e d p a r a m e t e r s f o r b o t h c o m p o n e n t s A a n d B . ( a ) L i f e t i m e s , ( b ) p e a k i n t e n -s i t i e s , ( c ) p e a k m a x i m a , ( d ) p e a k h a l f w i d t h . S y n t h e t i c d a t a w i t h : 1 % R S D n o i s e , c o m p o n e n t B i n t e n s i t y = 1 0 , o t h e r p a r a m e t e r s a s i n T a b l e I . G u e s s v a l u e s u s e d : A = 1 2 . 3 u s , B = 1 2 3 u s . 87 3 . 5 M a x i m u m e r r o r i n e s t i m a t e d p a r a m e t e r s f o r c o m p o n e n t A o n l y . ( a ) L i f e t i m e s , ( b ) p e a k i n t e n s i t y , ( c ) p e a k m a x i m a , ( d ) p e a k h a l f w i d t h s . S y n t h e t i c d a t a w i t h : 1 % R S D n o i s e , c o m p o n e n t B i n t e n s i t y = 1 0 , o t h e r p a r a m e t e r s a s i n T a b l e I . G u e s s v a l u e s u s e d : A = 1 2 . 3 u s , B = 123 u s . 88 3 . 6 M a x i m u m e r r o r i n e s t i m a t e d p a r a m e t e r s f o r c o m p o n e n t B o n l y . ( a ) L i f e t i m e s , ( b ) p e a k i n t e n s i t y , ( c ) p e a k m a x i m a , ( d ) p e a k h a l f w i d t h s . S y n t h e t i c d a t a w i t h : 1 % R S D n o i s e , c o m p o n e n t B i n t e n s i t y = 1 0 , o t h e r p a r a m e t e r s a s i n T a b l e I . G u e s s v a l u e s u s e d : A = 1 2 . 3 u s , B = 123 u s . 89 3 . 7 M a x i m u m e r r o r i n e s t i m a t e d p a r a m e t e r s f o r b o t h c o m p o n e n t s A a n d B a s a f u n c t i o n o f a d d e d n o i s e . ( a ) n o n o i s e a d d e d , ( b ) 1% R S D , ( c ) 2% R S D , ( d ) 3% R S D , ( e ) 4% R S D , ( f ) 5% R S D . S y n t h e t i c d a t a w i t h : c o m p o n e n t B i n t e n s i t y = 1 0 , o t h e r p a r a m e t e r s a s i n T a b l e I . G u e s s v a l u e s u s e d : A = 1 2 . 3 u s , B = 123 u s . 91 3 . 8 M a x i m u m e r r o r i n e s t i m a t e d p a r a m e t e r s f o r b o t h c o m p o n e n t s A a n d B a s a f u n c t i o n o f l i f e t i m e g u e s s v a l u e s . G u e s s v a l u e s ( u s ) u s e d : ( a ) 1 2 . 3 , 1 2 3 ; ( b ) 1 2 . 3 , 1 . 2 3 ; ( c ) 1 2 . 3 , 7 . 8 9 ; ( d ) 1 2 3 , 1 . 2 3 . S y n t h e t i c d a t a w i t h : 1 % R S D n o i s e , c o m p o n e n t B i n t e n s i t y = 1 0 , o t h e r p a r a m e t e r s a s i n T a b l e I . 92 i x F i g u r e D e s c r i p t i o n P a g e 3 . 9 M a x i m u m e r r o r i n e s t i m a t e d p a r a m e t e r s f o r b o t h c o m p o n e n t s A a n d B a s a f u n c t i o n o f p e a k i n t e n s i t y . P e a k i n t e n s i t i e s u s e d : ( a ) A = 1 0 , B = 5 0 ; ( b ) A = 1 0 , B = 2 0 ; ( c ) A = 1 0 , B = 1 0 ; ( d ) A = 1 0 , B = 5 ; ( e ) A = 1 0 , B = 2 ; ( f ) A = 1 0 , B = 1. S y n t h e t i c d a t a w i t h 1 % R S D n o i s e , o t h e r p a r a m e t e r s a s i n T a b l e I . G u e s s v a l u e s u s e d : A = 1 2 . 3 u s , B = 123 u s . 94 3 . 1 0 P l o t o f r e s i d u a l e r r o r v s n u m b e r o f c o m p o n e n t s g u e s s e d . L i f e t i m e s , u s : A = 1 0 , B = 2 5 , C = 2 . 5 ; p e a k s e p a r a t i o n s r a n g e : A - B : 0 . 2 t o 0 . 6 h a l f -w i d t h s , A - C : 0 . 8 t o 1.2 h a l f w i d t h s ; 1% R S D n o i s e ; e q u a l p e a k i n t e n s i t i e s . 97 3 .11 M e a s u r e d s p e c t r a f o r S r ( M o 0 5 w . 9 5 ) ° 4 : ( a ) 1 9 3 n m e x c i t a t i o n ; (b) 248 nm e x c i t a t i o n . 98 3 . 1 2 D i f f e r e n c e s p e c t r a a s a f u n c t i o n o f t h e n u m b e r o f c o m p o n e n t s g u e s s e d f o r S r t M o ^ o s w . 9 5 ) ° 4 e x c i t e d a t 2 4 8 n m . ( a ) o n e ; ( b ) t w o ; ( c ) " t h r e e ; ( d ) f o u r c o m p o n e n t s . 99 4 .1 Q u a r t z c e l l l u m i n e s c e n c e s p e c t r a , 1 0 0 n s t o 2 0 0 0 n s , 3 5 0 nm t o 7 0 0 n m . ( a ) 1 9 3 nm e x c i t a t i o n , ( b ) 248 nm e x c i t a t i o n . 101 4 . 2 L u m i n e s c e n c e s p e c t r a , 1 9 3 nm e x c i t a t i o n , 3 5 0 t o 7 0 0 n m . ( a ) C a l c i u m m o l y b d a t e , 1 0 0 0 n s t o 2 0 0 0 0 n s . ( b ) C a l c i u m t u n g s t a t e , 1 0 0 0 n s t o 2 0 0 0 0 n s . ( c ) S t r o n t i u m m o l y b d a t e , 1 0 0 n s t o 2 0 0 0 n s . ( d ) S t r o n -t i u m t u n g s t a t e , 100 ns t o 2000 n s . 102 4 . 3 L u m i n e s c e n c e s p e c t r a , 2 4 8 nm e x c i t a t i o n , 3 5 0 t o 700 n m . ( a ) C a l c i u m m o l y b d a t e , 1 0 0 0 n s t o 2 0 0 0 0 n s . ( b ) C a l c i u m t u n g s t a t e , 1 0 0 0 n s t o 2 0 0 0 0 n s . ( c ) S t r o n t i u m m o l y b d a t e , 1 0 0 n s t o 2 0 0 0 n s . ( d ) S t r o n -t i u m t u n g s t a t e , 100 ns t o 2000 n s . 103 4 . 4 L u m i n e s c e n c e s p e c t r a , 1 9 3 nm e x c i t a t i o n , 3 5 0 t o 700 n m . ( a ) Z i n c m o l y b d a t e , 1 0 0 n s t o 2 0 0 0 n s , ( b ) Z i n c t u n g s t a t e , 1 0 0 0 n s t o 2 0 0 0 0 n s , ( c ) C a d m i u m m o l y b d a t e , 1 0 0 n s t o 2 0 0 0 n s , ( d ) C a d m i u m t u n g -s t a t e , 1000 n s t o 2 0 0 0 0 n s . 106 4 . 5 L u m i n e s c e n c e s p e c t r a , 2 4 8 nm e x c i t a t i o n , 3 5 0 t o 700 n m . ( a ) Z i n c m o l y b d a t e , 1 0 0 n s t o 2 0 0 0 n s , ( b ) Z i n c t u n g s t a t e , 1 0 0 n s t o 2 0 0 0 n s , ( c ) C a d m i u m m o l y b d a t e , 1 0 0 n s t o 2 0 0 0 n s , ( d ) C a d m i u m t u n g -s t a t e , 1000 ns t o 2 0 0 0 0 n s . 107 x F i g u r e D e s c r i p t i o n P a g e 4 . 6 L u m i n e s c e n c e s p e c t r a , 1 9 3 nm e x c i t a t i o n , 1 0 0 0 n s t o 2 0 0 0 0 n s , 3 5 0 n m t o 7 0 0 n m . ( a ) C a W G - 4 , ( b ) C a ( M o 02 w 9 8 ) ° 4 f ( c > C a ( M o -| W 9 ) 0 4 , ( a ) C a ( M o t 2 W * # 8 ) 0 4 , * (e ) C a ( M o < 3 w # 8 ) 0 4 , * ( f ) C a M o 0 4 . 110 4 . 7 L u m i n e s c e n c e s p e c t r a , 1 9 3 nm e x c i t a t i o n , 1 0 0 n s t o 2 0 0 0 n s , 3 5 0 n m t o 7 0 0 n m . ( a ) S r W 0 4 , d) 4 . 8 ( b ) S r ( M o 02 W 9 8 ) 0 4 , ( c ) S r ( M o -| W 9 ) 0 4 , ( ) S r ( M o > 2 W \ 8 ) 0 4 , * (e) S r ( M o e 3 W f 8 ) 0 4 , * ( f ) S r M o 0 4 . 111 L u m i n e s c e n c e s p e c t r a , 2 4 8 nm e x c i t a t i o n , 1 0 0 n s t o 2 0 0 0 n s , 3 5 0 n m t o 7 0 0 n m . ( a ) S r W O * , ( b ) S r ( M o 02 w 9 8 ) ° 4 f ( c ) S r ( M o j W 0 g ) O 4 f ( a ) S r ( M o > 2 W * . 8 ) 0 4 , * (e) S r ( M o . 3 W . 8 ) 0 4 , * ( f ) * S r M o 0 4 . 112 4 . 9 R e l a t i o n s h i p b e t w e e n t u n g s t a t e l i f e t i m e a n d m o l y b -d a t e t o t u n g s t a t e r a t i o i n m i x e d c r y s t a l s , 1 9 3 nm e x c i t a t i o n , ( a ) S r ( M o , W ) 0 4 s y s t e m , ( b ) C a ( M o , W ) 0 4 s y s t e m . 114 4 . 1 0 S u p r a s i l d i s c l u m i n e s c e n c e s p e c t r a , 5 0 n s t o 1 000 n s . ( a ) 1 9 3 nm e x c i t a t i o n , 2 6 5 nm t o 5 1 0 n m . ( b ) 1 9 3 nm e x c i t a t i o n , 3 0 0 t o 7 9 0 n m . ( c ) 2 4 8 nm e x c i t a t i o n , 2 6 5 nm t o 5 1 0 n m . ( d ) 2 4 8 nm e x c i -t a t i o n , 300 nm t o 790 n m . 119 4 . 1 1 C a l c i u m z i r c o n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 7 0 nm t o 7 6 0 nm (b ) T l d o p e d , 5 0 0 n s t o 1 0 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 2 0 4 . 1 2 C a l c i u m z i r c o n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 7 0 nm ( b ) T l d o p e d , 5 0 0 n s t o 1 0 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 51 0 nm 1 21 4 . 1 3 C a l c i u m z i r c o n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 22 x i F i g u r e D e s c r i p t i o n P a g e 4 . 1 4 C a l c i u m z i r c o n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 2 3 4 . 1 5 S t r o n t i u m z i r c o n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 0 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 5 0 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 2 4 4 . 1 6 S t r o n t i u m z i r c o n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 7 0 nm t o 4 2 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 2 5 4 . 1 7 S t r o n t i u m z i r c o n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 0 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 0 0 nm 1 2 6 4 . 1 8 S t r o n t i u m z i r c o n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 5 4 5 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 5 4 5 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 2 7 4 . 1 9 B a r i u m z i r c o n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 n m ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm (d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 0 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 2 8 4 . 2 0 B a r i u m z i r c o n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 5 0 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 0 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 2 9 x i i F i g u r e D e s c r i p t i o n P a g e 4 . 2 1 B a r i u m z i r c o n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 0 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 0 0 nm 1 3 0 4 . 2 2 B a r i u m z i r c o n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 n m ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 n m ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 5 4 5 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 131 4 . 2 3 C a l c i u m h a f n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 3 2 4 . 2 4 C a l c i u m h a f n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 3 3 4 . 2 5 C a l c i u m h a f n a t e ; e x c i t a t i o n : 2 48 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 3 4 4 . 2 6 C a l c i u m h a f n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 3 5 4 . 2 7 S t r o n t i u m h a f n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 3 6 x i i i F i g u r e D e s c r i p t i o n * P a g e 4 . 2 8 S t r o n t i u m h a f n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 0 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 0 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 0 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 0 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 0 0 nm 1 3 7 4 . 2 9 S t r o n t i u m h a f n a t e ; e x c i t a t i o n : 2 48 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 0 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 2 0 0 0 n s t o 4 0 0 0 0 n s , 3 5 0 nm t o 7 0 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 3 8 4 . 3 0 S t r o n t i u m h a f n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 1 0 0 n s t o 2 0 0 0 n s , 3 0 0 nm t o 5 4 5 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 5 4 5 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 5 4 5 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 0 0 nm 1 3 9 4 . 3 1 B a r i u m h a f n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 4 0 4 . 3 2 B a r i u m h a f n a t e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 141 4 . 3 3 B a r i u m h a f n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 4 2 4 . 3 4 B a r i u m h a f n a t e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 4 3 x i v F i g u r e D e s c r i p t i o n P a g e 4 . 3 5 C a l c i u m o x i d e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 4 4 4 . 3 6 C a l c i u m o x i d e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 4 5 4 . 3 7 C a l c i u m o x i d e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 5 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 4 6 4 . 3 8 C a l c i u m o x i d e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 51 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 4 7 4 . 3 9 S t r o n t i u m o x i d e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 1 0 0 n s t o 2 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) - T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 1 0 0 n s t o 2 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 4 8 4 . 4 0 S t r o n t i u m o x i d e ; e x c i t a t i o n : 1 9 3 n m . ( a ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 n m ( d ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 51 0 nm 1 49 4 . 4 1 S t r o n t i u m o x i d e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 50 x v F i g u r e D e s c r i p t i o n P a g e 4 . 4 2 S t r o n t i u m o x i d e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 151 4 . 4 3 B a r i u m o x i d e ; e x c i t a t i o n : 1 9 3 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) S b d o p e d , 5 0 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 5 2 4 . 4 4 B a r i u m o x i d e ; e x c i t a t i o n : 1 93 n m . ( a ) n o d o p a n t , 1 0 0 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 1 0 0 n s t o 1 0 0 0 n s , 2 6 5 nm t o 51 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 5 3 4 . 4 5 B a r i u m o x i d e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 3 0 0 nm t o 7 9 0 nm 1 54 4 . 4 6 B a r i u m o x i d e ; e x c i t a t i o n : 2 4 8 n m . ( a ) n o d o p a n t , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( b ) T l d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( c ) S b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( d ) P b d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm ( e ) B i d o p e d , 50 n s t o 1 0 0 0 n s , 2 6 5 nm t o 5 1 0 nm 1 5 5 x v i ACKNOWLEDGEMENTS T h i s w o r k , i s d e d i c a t e d t o m y d a u g h t e r s S h i r l e y a n d A l i s o n t o m a k e u p f o r a l l t h o s e m i s s e d p i c n i c s , m o u n t a i n h i k e s , S c r a b b l e g a m e s , a n d o t h e r f u n t i m e s . A v e r y s p e c i a l t h a n k s t o m y w i f e F r a n c e s f o r h e r p e r s e v e r a n c e , s u p p o r t , a n d e n c o u r a g e m e n t t h r o u g h o u t t h i s e x e r c i s e . A s i n c e r e t h a n k y o u t o M i k e B l a d e s , m y r e s e a r c h s u p e r v i s o r , f o r h i s g u i d a n c e , s t i m u l a t i n g d i s c u s s i o n s , a n d s u p p o r t f o r t h i s p r o j e c t . I a l s o w a n t t o t h a n k m e m b e r s o f t h e m e c h a n i c a l a n d e l e c t r o n i c s s h o p s f o r t h e i r i n v a l u a b l e t e c h n i c a l s u p p o r t , E l m e r O g r y z l o f o r u s e o f h i s l a b o r a t o r y , a n d o t h e r m e m b e r s o f t h e C h e m i s t r y D e p a r t m e n t f o r t h e i r e n c o u r a g e m e n t a n d a d v i c e . x v i i Chapter 1 INTRODUCTION 1 .1 OVERVIEW S i n c e t h e r e s e a r c h d e s c r i b e d i n t h i s t h e s i s i s m a i n l y c o n c e r n e d w i t h l u m i n e s c n e c e , t h e b a s i c p r i n c i p l e s o f t h i s phenomenon a r e f i r s t d i s c u s s e d , w i t h an emphasis on p r o c e s -ses o c c u r r i n g i n s o l i d i n o r g a n i c i n s u l a t o r s . A b r i e f s k e t c h o f p r e - t w e n t i e t h c e n t u r y human e x p e r i e n c e s w i t h l u m i n e s c e n c e phenomena i s a l s o g i v e n , t o put t h i s work i n p e r s p e c t i v e . 1.2 HISTORICAL Luminescence i s t h e e m i s s i o n o f e l e c t r o m a g n e t i c r a d i a -t i o n from a s u b s t a n c e t h a t i s i n e x c e s s o f t h e r m a l l y i n d u c e d b l a c k b o d y r a d i a t i o n . P r e h i s t o r i c humans p r o b a b l y a s s o c i a t e d o b j e c t s e m i t t i n g l i g h t w i t h h e a t s i n c e i n t h e i r e v e r y d a y e x p e r i e n c e s a l l common l i g h t s o u r c e s were i n c a n d e s c e n t b l a c k body r a d i a t o r s such as f i r e , g l o w i n g embers and t h e sun [ 1 ] . L u m i n e s c e n c e , o r " c o l d " l i g h t , was a d i s t i n c t l y u n u s u a l phenomenon t h a t g e n e r a l l y i n d u c e d awe and f e a r i n o u r a n c e s t o r s [ 2 ] . The r e c o g n i t i o n o f l u m i n e s c e n c e a s a d i s t i n c t p h y s i c a l phenomenon was l i k e l y f i r s t a s s o c i a t e d w i t h t h e a u r o r a b o r e a l i s and b i o l u m i n e s c e n c e . The a u r o r a b o r e a l i s i s a s t r i k i n g phenomenon o f t r a n -s i e n t gas phase l u m i n e s c e n c e [3] a p p e a r i n g i n t h e n i g h t sky a g a i n s t t h e b a c k g r o u n d o f f i x e d s t a r s . I n many a n c i e n t c u l t u r e s t h e a p p e a r a n c e o f t h e a u r o r a b o r e a l i s was o f t e n t a k e n t o be an omen s i n c e i t i s an u n u s u a l phenomenon i n t e m p e r a t e l a t i t u d e s and a d i s t i n c t r a r i t y i n t h e t r o p i c s 1 [3], In temperate and t r o p i c a l regions the aurora i s normally a deep red c o l o r . To the a n c i e n t s , t h i s deep red c o l o r was o f t e n a s s o c i a t e d with blood and a d i s p l a y of the aurora borealis was invariably linked with impending doom or some other s i g n i f i c a n t change for the worse i n human events [ 4 ] , In p o l a r l a t i t u d e s where the aurora i s an everyday occurrence benign associations with the aurora are the rule. For example, among the Inuit, a legend common to many tribes around the A r c t i c [4] a s c r i b e s the c o l o r e d bands of the aurora to t h e i r ancestors' s p i r i t s p l a y i n g b a l l with a walrus s k u l l . Bioluminescence was evident to early humans i n several d i s t i n c t and sometimes unusual forms. Glowworms and f i r e -f l i e s g e n e r a l l y heralded the a r r i v a l of summer i n damp, temperate regions. Luminescence produced by luminescent b a c t e r i a i n r o t t i n g wood and p u t r e f y i n g f l e s h were note-worthy events that o f t e n c a r r i e d r e l i g i o u s overtones [ 2 ] . To ancient Chinese s e a f a r e r s , the appearance of "burning seas" caused by luminescent plankton was a t t r i b u t e d to either dragons or the gods. Reports of precious stones that shine i n the dark are scattered throughout early l i t e r a t u r e [ 5 , 6 ] . These reports tended to be h i g h l y embellished accounts of gemstones' r e f r a c t i v e power and cut, although f l u o r s p a r and c e r t a i n types of thermoluminescent diamond may have been observed a l s o . The luminous cobra stone of India and S r i Lanka [2] was l i k e l y a type of thermoluminescent f l u o r i t e . Western 2 scholars such as A r i s t o t l e , Herodotus, and Thales of Miletus [7] gave accounts of luminescent phenomena but did not make di r e c t reference to luminescent stones. 1.2.1 THE BOLOGNA STONE Sometime between 1602 and 1604 Vincenzo Casciorolo [5], a Bolognian cobbler and amateur alchemist, made one of the most s i g n i f i c a n t d i s c o v e r i e s [2] i n the f i e l d of lumine-scence. C a s c i o r o l o found a heavy, t r a n s l u c e n t mineral on the slopes of Monte Paterno near Bologna that would, on c a l c i n a t i o n , shine i n the dark a f t e r exposure to e i t h e r s u n l i g h t or c a n d l e l i g h t . The stone's r e d d i s h c o l o r e d luminescence, l i k e that of a glowing ember, would gradually fade away and cease to glow a f t e r a p e r i o d of time. The substance Casciorolo found was a sulf u r r i c h form of heavy spar that became contaminated with a small amount of barium s u l f i d e on c a l c i n a t i o n . Over a p e r i o d of time, the stone would e v e n t u a l l y l o s e i t s a b i l i t y to luminesce due to absorption of moisture from the atmosphere [21. The d i s c o v e r y of the Bologna stone was a s i g n i f i c a n t event i n h i s t o r y , f o r i t was the f i r s t a r t i f i c i a l l i g h t storage device. I t i s the d i r e c t precursor of devices such as the f l u o r e s c e n t lamp, cathode ray tube, and the s o l i d s t a t e l a s e r . However, of even more importance i s the philosophical impact t h i s material had on human thought for i t gave d i r e c t evidence that l i g h t was a material substance. T h i s c o n c e p t of l i g h t b e i n g a m a t e r i a l s u b s t a n c e i s comparable to the concept of the w a v e - p a r t i c l e d u a l i t y of 3 matter i n modern physics. The physical evidence exhibited by the Bologna stone d i s c r e d i t e d the P l a t o n i c concept of ocular beams [8] emanating from the eye and the Neoplatonist argument of l i g h t as the " i l l u m i n a t i o n of the human i n t e l l e c t by divine truth". The Bologna stone phosphor was studied by leading 17th century s c i e n t i s t s and philosophers i n c l u d i n g G a l i l e o , L i c e t i and La G a l l a . Luminescence from the Bologna stone gave G a l i l e o [9] p h y s i c a l evidence that the contemporary philosophical b e l i e f s that l i g h t was a quality of a transpa-rent, i l l u m i n a t e d medium were f a l s e . In 1652, N i c o l a i Zucchi of C o l l e g i o Romano reported i n Optica P h i l o s o p h i a that the luminescence i n t e n s i t y from the Bologna stone was proportional to the i n t e n s i t y of the ex c i t i n g l i g h t and that the stone's luminescence c o l o r was independent of the e x c i t i n g l i g h t c o l o r . On the b a s i s of h i s experiments, Z u c c h i [2] made the c o n c l u s i o n : " L i g h t i s not merely absorbed as such, but r a t h e r i t e x c i t e s and u n i t e s with a s p i r i t o u s substance contained i n the stone, and when the ill u m i n a t i o n has ceased, t h i s substance gradually dissipates and becomes unsuitable for exhibiting a v i s i b l e glow". Thus the foundations of luminescence spectroscopy were l a i d . The f i r s t recorded observation of a luminescence spec-trum from an inorganic substance was made by Francesco Maria Zanotti i n collaboration with Count Francesco A l g a r o t t i i n 1713 [2], They repeated Zucchi's experiment using a prism t o d i s p e r s e the l u m i n e s c e n c e from the Bologna stone 4 phosphor. The dim, apparently monochromatic emission was noted. However, a true idea of the luminescence spectrum was not gained due to low l i g h t i n t e n s i t y and the lack of an entrance s l i t i n t h e i r apparatus. 1.2.2 CONTRIBUTIONS OF BECQUEREL AND STOKES The next major advance i n luminescence studies was made in the mid nineteenth century when the s c i e n t i f i c treatment of the s u b j e c t was pursued i n earnest. Antoine Cesar Becquerel, i n collaboration with his son Edmond, published the f i r s t drawings of luminescence spectra i n volume II of h i s " T r a i t e de Physique" ( P a r i s , 1844) i n which he showed emission from calcium and barium s u l f i d e s along with a solar spectrum containing the Fraunhofer l i n e s for comparison. Edmond Becquerel's extensive experimental work l a i d the foundation for the s c i e n t i f i c investigation of luminescence [10]. He was the dominant f i g u r e of h i s time with h i s s t u d i e s on e x c i t a t i o n and emission s p e c t r a as w e l l as h i s invention of the phosphoroscope for the study of luminesc-ence l i f e t i m e s . With his phosphoroscope, which was capable of l i f e t i m e measurements as short as 0.1 ms, Becquerel esta-b l i s h e d the decay law with h i s f i n d i n g s that luminescence i n t e n s i t y decreased e x p o n e n t i a l l y as a f u n c t i o n of time. Becquerel recorded the f i r s t observations of time-wavelength resolved luminescence [10] with his descriptions of substan-ces s t u d i e d with h i s phosphoroscope whose luminescence changed color with time. In a landmark paper, G. G. Stokes [11 ] coined the term 5 " f l u o r e s c e n c e " a f t e r t h e l i g h t e m i t t e d f r o m t h e m i n e r a l f l u o r s p a r a n d p r o v i d e d t h e c o r r e c t i n t e r p r e t a t i o n o f f l u o r e -s c e n c e i n s o l u t i o n s b e i n g t h e o p t i c a l e m i s s i o n o f l i g h t r a t h e r t h a n s c a t t e r i n g . I n t h i s p a p e r , h e s t a t e d t h e p r i n c i p l e t h a t h a s b e c o m e k n o w n a s " S t o k e s ' L a w " : f l u o r e s c e n t l i g h t i s a l w a y s o f l o n g e r w a v e l e n g t h t h a n t h e l i g h t u s e d t o e x c i t e a l u m i n e s c e n t s u b s t a n c e o r s o l u t i o n . I n f o r m u l a t i n g t h i s p r i n c i p l e , S t o k e s u s e d a m u l t i -d i m e n s i o n a l a p p r o a c h : t h e m e t h o d o f s p e c t r a l i l l u m i n a t i o n o r " c r o s s e d s p e c t r a " w h e r e t h e e x c i t a t i o n l i g h t p a s s e d t h r o u g h a p r i s m t o i l l u m i n a t e a s a m p l e i n s u c h a m a n n e r t h a t f l u o -r e s c e n c e f r o m t h e s a m p l e b y a n y e x c i t a t i o n w a v e l e n g t h may b e o b s e r v e d . I n a s e q u e l [ 1 2 ] , S t o k e s d e s c r i b e d a s i m p l e y e t e l e g a n t f l u o r e s c e n c e s p e c t r o m e t e r f o r c h e m i c a l a n a l y s i s a n d r e p o r t e d p r e l i m i n a r y w o r k d o n e u s i n g t h i s i n s t r u m e n t . T h r o u g h t h e e f f o r t s o f E . B e c q u e r e l a n d G . S t o k e s l u m i n e s c e n c e s p e c t r o s c o p y b e c a m e f i r m l y e s t a b l i s h e d a s a m a j o r a r e a o f s t u d y t h a t h a s h a d p r o f o u n d i n f l u e n c e i n d i v e r s e f i e l d s s u c h a s a r c h a e o l o g y , n u c l e a r p h y s i c s , q u a n t u m p h y s i c s , b i o c h e m i s t r y a n d a r t c o n s e r v a t i o n . 1.3 L U M I N E S C E N C E OF AN I S O L A T E D ATOM T h e s i m p l e s t e l e c t r o n i c s y s t e m c a p a b l e o f e m i t t i n g l i g h t , a s i d e f r o m a n a c c e l e r a t i n g e l e c t r o n , i s a s i n g l e i s o l a t e d a t o m . T h i s a t o m may b e e x c i t e d t o a h i g h e r e n e r g y l e v e l a b o v e i t s g r o u n d s t a t e b y t w o p r i n c i p a l p r o c e s s e s . T h e f i r s t p r o c e s s , k n o w n a s k i n e t i c o r t h e r m a l e x c i t a t i o n , i n v o l v e s a n i n e l a s t i c c o l l i s i o n w i t h a n o t h e r p a r t i c l e w h e r e 6 some o f t h e p a r t i c l e ' s k i n e t i c energy i s t r a n s f e r r e d t o the atom, r a i s i n g t h e atom t o a h i g h e r energy l e v e l . The second e x c i t a t i o n p r o c e s s i n v o l v e s a b s o r p t i o n o f a p h o t o n whose energy c l o s e l y matches t h a t o f a t r a n s i t i o n f r om t h e ground s t a t e t o an e x c i t e d s t a t e o f t h e atom. When t h e e x c i t e d atom r e l a x e s t o a l o w e r energy s t a t e by photon e m i s s i o n , the e m i s s i o n i s s a i d t o be t h e r m a l l y s t i m u l a t e d i f e x c i t a t i o n was by t h e f i r s t p r o c e s s and l u m i n e s c e n c e i f e x c i t a t i o n was by t h e s e c o n d p r o c e s s . I n an atom, i f t h e e m i t t e d p h o t o n has t h e same e n e r g y as t h e e x c i t i n g p h o t o n , t h e e m i t t e d l i g h t i s t e r m e d r e s o n a n c e r a d i a t i o n [ 1 3 ] . K i n e t i c and r a d i a t i v e p r o c e s s e s may o c c u r e i t h e r s i n g l y o r i n c o m b i n a t i o n , as i l l u s t r a t e d i n F i g u r e 1.1. 1.3.1 EINSTEIN THEORY OF RADIATION I f an i s o l a t e d atom c a p a b l e o f b e i n g r a i s e d f r o m an e n e r g y s t a t e 1 t o a h i g h e r e n e r g y s t a t e 2 i s i n a c o n t a i n e r c o n t a i n i n g i s o t r o p i c r a d i a t i o n o f f r e q u e n c y b e t w e e n v and v + dv a n d i n t e n s i t y I v , t h e f o l l o w i n g p r o b a b i l i t y c o e f f i c i e n t s may be d e f i n e d [ 1 3 ] : B-|2l v i s the p r o b a b i l i t y t h a t t h e atom i n energy s t a t e 1 w i l l a b s o r b a quantum hv and p a s s t o e n e r g y s t a t e 2 when i t i s exposed t o t h e i s o t r o p i c r a d i a t i o n . A21 i s t h e p r o b a b i l i t y t h a t t h e atom i n energy s t a t e 2 w i l l s p o n t a n e o u s l y e m i t w i t h o u t s p a t i a l coherence a quantum hv and pass t o energy s t a t e 1. B 2 1 I v ^ s t h e p r o b a b i l i t y t h a t t h e atom w i l l e m i t a quantum hv s p a t i a l l y c o h e r e n t w i t h t h e s t i m u l a t i n g quantum 7 Figure 1.1 Luminescence processes i n atoms: (A) resonance f l u o r e s c e n c e , (B) d i r e c t l i n e f l u o r e s c e n c e , (C) t h e r m a l l y a s s i s t e d d i r e c t l i n e f l u o r e s -cence, (D) thermally assisted resonance f l u o -rescence, (E) stepwise l i n e fluorescence, (F) thermally assisted stepwise l i n e fluorescence. 8 hv' when i t i s exposed to the i s o t r o p i c radiation. In the case where l o c a l thermodynamic equilibrium (LTE) exists i n the container: ( A21)/(B-| 2) = ( 2 h v 3 / c 2 ) ( g i / g 2 ) (1.1) (B 2 1 ) / ( B 1 2 ) = (g<i/g2) H..2) where g-j and g 2 are the s t a t i s t i c a l weights of the energy s t a t e s 1 and 2 r e s p e c t i v e l y , h i s Planck's constant, and c i s the speed of l i g h t . From the d e f i n i t i o n of the term A2-|, the l i f e t i m e of the atom i n energy state 2, T , i s : T = 1/(A 2 1) (1.3) and f o r the t r a n s i t i o n from an energy s t a t e n to a l l lower energy s t a t e s m, the l i f e t i m e of the atom ( t n ) i n energy s t a t e n i s : Tn = V ( Z A ^ ) H . 4 ) Thus, f o r an is o l a t e d atom that i s not subject to perturbing influences such as c o l l i s i o n s or external force f i e l d s , the excited state w i l l have a l i f e t i m e that i s c h a r a c t e r i s t i c of the atom and the p a r t i c u l a r e x c i t e d s t a t e that the atom i s i n . 1.3.2 NATURAL LINE BROADENING If one observes many emission events occurring between the same energy l e v e l s from t h i s i s o l a t e d atom, one w i l l see that the emitted photons are not i d e n t i c a l i n energy. The 9 s l i g h t energy v a r i a t i o n i n the photon energy i s a conse-quence of the Heisenberg uncertainty p r i n c i p l e . Since the atom spends on the average a time t i n the excited state i t i s i m p o s s i b l e to know e x a c t l y the energy of the e x c i t e d state. The excited state may have an energy anywhere i n the i n t e r v a l E ± (h/2Trt) / where E i s the average energy of the e x c i t e d s t a t e , h i s Planck's constant and t i s the average time the atom stays i n the excited state. For an atom undergoing a radi a t i v e t r a n s i t i o n between energy l e v e l s 2 and 1, the natural damping factor Y N * S ; Y N = (1/TT ) + (1/T 2) <1-5) where x-| and x 2 are the mean l i f e t i m e s f o r energy s t a t e s 1 and 2 respectively. The energy d i s t r i b u t i o n of photons for th i s t r a n s i t i o n [14] i s : = Y N / t 4 7 r 2 ( v " v 0 ) 2 + (Y N/2) 2] d.6) where <J>V represents the pr o b a b i l i t y of photon emission at a frequency v and V Q i s the mean frequency of photons emitted. 1 . 4 LUMINESCENCE OF ATOMS IN A GAS Consider a transparent c o n t a i n e r of gas c o n s i s t i n g of atoms of one type, say mercury, along with other kinds of atoms and molecules. This system i s considerably more com-plex than that of a single i s o l a t e d atom, since the mercury atoms w i l l be i n motion and be involved i n c o l l i s i o n s with other mercury atoms as well as other species present i n the conta i n e r . Luminescence from the mercury atoms w i l l be 10 i n f l u e n c e d b y i n t e r a c t i o n s w i t h i t s n e i g h b o r s i n many w a y s , some o f w h i c h a r e d i s c u s s e d i n t h e f o l l o w i n g s e c t i o n s . 1.4.1 S P E C T R A L L I N E BROADENING E F F E C T S I n a g a s , t h e l u m i n e s c e n c e f r o m a g i v e n t r a n s i t i o n b e t w e e n e n e r g y s t a t e s 2 a n d 1 i s s u b j e c t t o b r o a d e n i n g e f f e c t s d u e t o t h e D o p p l e r e f f e c t a n d c o l l i s i o n s w i t h o t h e r c o n s t i t u e n t s o f t h e g a s m i x t u r e . A s s u m i n g t h a t s t r o n g m a g -n e t i c f i e l d s a r e a b s e n t a n d t h e n u m b e r o f i o n s p r e s e n t i s n e g l i g i b l e , Z e e m a n a n d S t a r k b r o a d e n i n g e f f e c t s may b e i g n o r e d . D o p p l e r b r o a d e n i n g i s p r o d u c e d b y t h e e m i t t i n g a t o m s m o v i n g a b o u t i n s p a c e a t d i f f e r e n t v e l o c i t i e s , w i t h o u t c o n -s i d e r a t i o n o f e f f e c t s i n d u c e d b y c o l l i s i o n s . A s s u m i n g a G a u s s i a n v e l o c i t y d i s t r i b u t i o n f o r e m i t t i n g a t o m s i n t h e g a s , a D o p p l e r b r o a d e n e d s p e c t r a l l i n e i s s y m m e t r i c a b o u t t h e c e n t e r o f t h e l i n e w i t h a p r o f i l e , <)>V(j, d e s c r i b e d b y t h e r e l a t i o n s h i p [ 1 4 , 1 5 ] : * v d = { e x P - [ ( v - v o ) / A V D ] } / ( T T 2 A V D ) ( 1 . 7 ) w h e r e t h e D o p p l e r w i d t h , A v D , t h e f r e q u e n c y s h i f t o f t h e m o s t p r o b a b l e v e l o c i t y , i s : A v D = ( v 0 / c ) [ ( 2 k T / M ) + V t 2 ] 2 ( 1 . 8 ) w h e r e k i s B o l t z m a n n ' s c o n s t a n t , T i s t e m p e r a t u r e , M i s m a s s o f t h e e m i t t i n g a t o m , a n d V t i s t h e t u r b u l e n t v e l o c i t y o f t h e g a s . C o l l i s i o n i n d u c e d l i n e b r o a d e n i n g e f f e c t s a r e d u e t o 11 the perturbation of energy l e v e l s i n the atom caused by the e l e c t r i c f i e l d s of nearby atoms and molecules. C o l l i s i o n broadening of an atomic l i n e i s a complex process. The observable e f f e c t s being o v e r a l l broadening of the spectral l i n e , a s h i f t i n the l i n e maxima and an asymmetric int e n s i t y d i s t r i b u t i o n about the l i n e maxima. This complex topic has been s t u d i e d i n d e t a i l by the a s t r o p h y s i c a l community [1,16,17] and has l e d to an understanding of p h y s i c a l and chemical processes i n astronomical objects. To a f i r s t approximation, i f the gas i n the container i s at standard temperature and pressure (STP), the lumines-cence l i n e p r o f i l e I Y / a t frequency v, from an atom may be described by the Voigt equation [15]: I v = I 0 ( a ' / T r ) / " o J e x p f - y 2 ) ] / ^ 2 + (u - y ) 2 ] dy (1.9) where: u> = 2 ( v - v 0 ) ( l n 2 ) 2 / A v D (1.10) a' = (Av N + Av L)(ln2 ) 2/Av D (1.11) y = 26(ln2 ) 5/Av D (1.12) Av L = Z L / T T (1.13) and I Q i s the i n t e n s i t y at the peak maximum, 6 i s the frequency displacement from V - V Q , i s the number of broadening c o l l i s i o n s per second per luminescent atom. The approximations f o r the Lorentz halfwidth, Av L, and the form of the Voigt equation y i e l d a l i n e p r o f i l e that i s symmetric with no o f f s e t i n peak emission wavelength. Despite these l i m i t a t i o n s , t h i s model for the l i n e p r o f i l e 12 i s u s e f u l i n s t u d i e s o f p o t e n t i a l s p e c t r a l o v e r l a p p r o b l e m s i n a n a l y t i c a l a p p l i c a t i o n s . 1.4.2 QUANTUM Y I E L D S AND E X C I T E D S T A T E L I F E T I M E S A s s u m i n g t h a t i n t r i n s i c n o n l i n e a r o p t i c a l p h e n o m e n a a r e n e g l i g i b l e [ 1 8 ] , t h e q u a n t u m y i e l d , $ , f o r l u m i n e s c e n c e may b e d e f i n e d a s t h e n u m b e r o f q u a n t a e m i t t e d p e r n u m b e r o f q u a n t a a b s o r b e d b y a s y s t e m o v e r a g i v e n p e r i o d o f t i m e . I n a n a t o m , t h e q u a n t u m y i e l d f o r a g i v e n t r a n s i t i o n may b e r e d u c e d b y t h e p r e s e n c e o f i n t e r m e d i a t e e x c i t e d s t a t e s , n o n r a d i a t i v e i n t e r n a l c o n v e r s i o n p r o c e s s e s , a n d n o n r a d i a t i v e e n e r g y t r a n s f e r t o a n o t h e r s p e c i e s p r e s e n t i n t h e g a s . I n t h e c a s e o f r e s o n a n c e f l u o r e s c e n c e i n a c o l l e c t i o n o f a t o m s i n w h i c h n o n r a d i a t i v e p r o c e s s e s a n d i n t e r m e d i a t e e x c i t e d s t a t e s a r e a b s e n t , i f t h e a t o m s a r e i n a n e x c i t e d s t a t e p , t h e y w i l l u n d e r g o d e c a y t o t h e g r o u n d s t a t e q a t a r a t e g i v e n b y t h e r e l a t i o n s h i p : - d n p / d t = A 2 1 n p ( 1 . 1 4 ) w h e r e n p i s t h e n u m b e r o f a t o m s i n t h e e x c i t e d s t a t e , A21 ^ s t h e E i n s t e i n t r a n s i t i o n p r o b a b i l i t y ( s e e s e c t i o n 1 .3 .1 ) f o r s p o n t a n e o u s t r a n s i t i o n f r o m t h e e x c i t e d s t a t e , p , t o t h e g r o u n d s t a t e q . I f t h e e x c i t i n g r a d i a t i o n i s s t o p p e d a t t i m e t=0, t h e n a t s o m e f u t u r e t i m e , t , t h e n u m b e r o f e x c i t e d a t o m s r e m a i n i n g i n t h e g a s , nj!j, m a y b e f o u n d b y s u b s t i t u t i n g l i f e t i m e f o r t r a n s i t i o n p r o b a b i l i t y ( 1 . 3 ) a n d i n t e g r a t i n g ( 1 . 1 4 ) : 13 nt = nOexp(-t/x) (1.15) In the case where the e x c i t e d atoms do not undergo i n t e r a c t i o n s with each other but do undergo r e l a x a t i o n by n o n r a d i a t i v e i n t e r n a l conversion processes, the i n t r i n s i c l i f e t i m e for the atom i s obtained by combining the tran-s i t i o n p r o b a b i l i t i e s f o r both r a d i a t i v e and n o n r a d i a t i v e t r a n s i t i o n s : T ° = 1/ZAp r (1.16) where Ap r i s the t r a n s i t i o n p r o b a b i l i t y for the t r a n s i t i o n between the excited energy state p and a lower state r. The case where c o l l i s i o n a l d e e x c i t a t i o n occurs along with i n t e r n a l conversion [19] i s t r e a t e d i n an analogous manner. If there are s v a r i e t i e s of atoms and molecules i n the gas, each having some c o n c e n t r a t i o n Q s, and i f the temporal p r o b a b i l i t y for c o l l i s i o n a l quenching by a species i s represented by k s, then the l i f e t i m e f o r atoms i n the excited state T ' , i s given by the relationship: T1 = 1/[ ZA p r + |k sQ s] (1.17) Equation 1.17 i s of fundamental importance, f o r i t shows that the l i f e t i m e of an e x c i t e d s t a t e i n a substance i s c h a r a c t e r i s t i c of that substance and the environment of the substance. In a d d i t i o n , i t provides an avenue f o r examining environmental e f f e c t s quantitatively. 14 1 . 5 GAS P H A S E MOLECULAR L U M I N E S C E N C E M o l e c u l e s h a v e a m o r e c o m p l e x e l e c t r o n i c s t r u c t u r e t h a n s i n g l e a t o m s ; t h i s i n c r e a s e d c o m p l e x i t y i s r e f l e c t e d i n t h e i r l u m i n e s c e n c e s p e c t r a a n d r e l a x a t i o n b e h a v i o r . M o s t g a s p h a s e m o l e c u l a r l u m i n e s c e n c e s t u d i e s [ 2 0 ] h a v e b e e n l i m i t e d t o a r o m a t i c o r g a n i c m o l e c u l e s . I n t h e g a s p h a s e , a t l o w p r e s s u r e s , a m o l e c u l e m a y b e c o n s i d e r e d t o b e a n i s o l a t e d s y s t e m w i t h n e g l i g i b l e i n t e r a c t i o n s w i t h o t h e r c o m p o n e n t s o f t h e g a s . I n o r g a n i c m o l e c u l e s , t h e l u m i n e s c e n c e p r o c e s s e s a r e i n v o l v e d p r i m a r i l y w i t h e x c i t e d s t a t e s o f T r - e l e c t r o n s y s t e m s i n t h e m o l e c u l e [ 2 1 ] a n d a r e a f u n c t i o n o f t h e m o l e c u l e ' s d e g r e e o f c o n j u g a t i o n , s h a p e , r i g i d i t y a n d f u n c t i o n a l s u b -s t i t u e n t s . O r g a n i c c o m p o u n d s s u c h a s a r o m a t i c h y d r o c a r b o n s , a m i n o a c i d s , a n d p o l y e n e s w h i c h c o n t a i n e x t e n s i v e d o u b l e b o n d s a r e p a r t i c u l a r l y w e l l d i s p o s e d t o l u m i n e s c e n c e . The J a b l o n s k i i d i a g r a m i n F i g u r e 1.2 o u t l i n e s t h e b a s i c l u m i n e s -c e n c e p r o c e s s e s i n o r g a n i c m o l e c u l e s . I n T r - e l e c t r o n s y s t e m s , t h e g r o u n d s t a t e n o r m a l l y c o n t a i n s a n e v e n n u m b e r o f e l e c t r o n s w h o s e s p i n s a r e p a i r e d , t h i s e n e r g y s t a t e i s t e r m e d a s i n g l e t s t a t e a n d i s s y m b o l i z e d a s "So"* T h e r e may b e s e v e r a l e x c i t e d s t a t e s , i n w h i c h c a s e t h e y a r e d e n o t e d a s S-j , S2r e t c . . I f s p i n r e v e r s a l o c c u r s o n e x c i t a t i o n t h e e x c i t e d s t a t e s a r e t e r m e d t r i p l e t s t a t e s s y m b o l i z e d a s T- | , T 2 , e t c . , w i t h t h e t r i p l e t s t a t e e n e r g y l e v e l a l w a y s l y i n g b e l o w i t ' s C o r r e s p o n d i n g s i n g l e t s t a t e l e v e l [ 2 2 ] , D i r e c t e l e c t r o n i c t r a n s i t i o n s 15 ' 2 x s.3 ABSORPTION FLUORESCENCE VIBRATIONAL RELAXATION • INTERSYSTEM CROSSING •4 PHOSPHORESCENCE F i g u r e 1 . 2 L u m i n e s c e n c e p r o c e s s e s i n 7 r - e l e c t r o n s y s t e m s . 16 between s i n g l e t and t r i p l e t states have very low t r a n s i t i o n p r o b a b i l i t i e s . Within each e l e c t r o n i c energy l e v e l l i e s a series of v i b r a t i o n a l sublevels. In organic molecules, the luminescence processes of fluorescence, which involves no change i n spin m u l t i p l i c i t y , and phosphorescence, where radi a t i v e emission i s accompanied by a change of spin m u l t i p l i c i t y , are r e a d i l y distinguished. The emission observed for an organic molecule i s p r i m a r i l y governed by the f o l l o w i n g r a t e p r o c e s s e s : Si+Srj/ fluorescence; S-i+Sn, in t e r n a l conversion; S1+T1, intersystem c r o s s i n g ; T ^ S Q / phosphorescence; T - J - ^ S Q / i n t e r s y s t e m crossing. The r e l a t i v e magnitudes of the rate constants are dependent on the o v e r a l l e l e c t r o n i c s t r u c t u r e of a p a r t i c u l a r molecule. The emission process i s highly dependent on the enviro-nment of the molecule. C o l l i s i o n a l deactivation e f f e c t s are dependent on the c h e m i c a l and p h y s i c a l n a t u r e of the concomitant as well as the c o l l i s i o n frequency. Phosphores-cence i s normally observed only at low temperatures and pressures s i n c e c o l l i s i o n a l d e - e x c i t a t i o n of the t r i p l e t s t a t e i s l i k e l y to occur before the two slow i n t e r s y s t e m crossings are made. However, i f a halogen i s present i n the gas or attached to the molecule, the r a t e constant f o r i n t e r s y s t e m c r o s s i n g w i l l be i n c r e a s e d s i g n i f i c a n t l y and phosphorescence may e f f e c t i v e l y compete w i t h the fluorescence process. Oxygen e f f e c t i v e l y quenches a l l types of luminescence i n organic molecules; the oxygen molecule 17 a p p a r e n t l y c a t a l y s e s [22] n o n r a d i a t i v e d e a c t i v a t i o n processes i n the molecule. Luminescence p r o c e s s e s i n o r g a n i c m o l e c u l e s a re intimately associated with the bonding within the molecule i t s e l f , r e g a r d l e s s of the p h y s i c a l s t a t e of the molecule. The fi n e structure observed for an is o l a t e d molecule may be altered by the presence of neighbors at increased pressures and i n condensed media, but the b a s i c s p e c t r a l p a t t e r n remains with r e l a t i v e l y s m a l l s h i f t s due to minor a l t e r a -tions i n the molecule's Tr-bonds induced by the neighbors. 1 .6 LUMINESCENCE IN THE SOLID STATE S o l i d s t a t e luminescence i s found i n a vast a r r a y of substances of inorganic and organic composition and i n both c r y s t a l l i n e and amorphous forms. Although there are nume-rous luminescence mechanisms i n s o l i d s , a common thread among them i s that luminescence emission i s a product of the elec t r o n i c energy l e v e l s of a s o l i d ; thus, the luminescence from a s o l i d c a r r i e s information on these energy l e v e l s . Luminescent s o l i d state materials may be grouped into three broad c l a s s i f i c a t i o n s : organic molecules, semiconduc-tors and inorganic insulators. The luminescence mechanisms dominant within each group d i f f e r so much between the groups that separate discussions are warranted for the events that follow the i n i t i a l excitation. 1.6.1 EXCITATION METHODS There are numerous methods f o r inducing luminescence emission i n a s o l i d . They may be broadly c l a s s i f i e d as: 18 r a d i a t i o n , thermal s t i m u l a t i o n , phase change, mechanical deformation, chemical r e a c t i o n , and superimposed e l e c t r i c f i e l d . E x c i t a t i o n of a s o l i d by i r r a d i a t i o n may be done with either nonionizing or i o n i z i n g radiation. Nonionizing exci-t a t i o n of s o l i d s with UV and v i s i b l e l i g h t i s d i s c u s s e d i n more d e t a i l i n succeeding sections. When a high energy (X-ray or gamma ray) photon or high energy subatomic p a r t i c l e such as an e l e c t r o n or proton passes through a s o l i d ; numerous complex processes [23] may be i n i t i a t e d such as: nuclear reactions, bond rupture, i o n i -z a t i o n , and d e f e c t formation as energy i s absorbed by the s o l i d . An end r e s u l t of these interactions i s the formation of e l e c t r o n - h o l e p a i r s i n the s o l i d . Subsequent to the formation of electron-hole pairs, energy release may proceed by: e l e c t r o n - h o l e recombination, t r a n s f e r by e x c i t o n s , or temporary storage i n hole trapping metastable energy lev e l s termed tr a p s . In each of these modes r e l a x a t i o n to the ground state may be by a combination of phonons and photons, with luminescence being the route of photon emission. Thermoluminescence i s the thermally stimulated lumines-cence emission i n a s o l i d from metastable energy s t a t e s known as traps. Traps i n a s o l i d are normally populated by i r r a d i a t i o n with high energy photons or subatomic p a r t i c l e s . The p r i n c i p a l applications have been i n age dating c u l t u r a l a r t i f a c t s and dosimetry. Crystalloluminescence and lyoluminescence involve phase 19 changes i n a m a t e r i a l . C r y s t a l l o l u m i n e s c e n c e [24] i s the f l a s h of l i g h t emitted from a substance as i t c r y s t a l l i z e s from a melt. This phenomenon i s responsible for the "b l i c k " occurring as the gold bead c r y s t a l l i z e s i n cupellation [25] and the " s h o t t i n g " from s o l i d i f y i n g s l a g i n the f i r e assay for gold. The f l a s h colors have been used by f i r e assayers q u a l i t a t i v e l y i n judging bead p u r i t y and assay charges. Lyoluminescence i s the l i g h t emission from traps as a s o l i d undergoes d i s s o l u t i o n . It's p r i n c i p a l a p p l i c a t i o n i s i n radiat i o n dosimetry. Triboluminescence [24,26] i s the l i g h t emitted from a s o l i d when i t undergoes mechanical deformation. Despite i t s i n t i m a t e connection with the mechanical, e l e c t r i c a l , and spectroscopic properties of materials, i t currently remains a laboratory c u r i o s i t y . Chemiluminescence occurs when a product of a chemical r e a c t i o n i s l e f t i n an e l e c t r o n i c a l l y e x c i t e d s t a t e and r e l a x e s by photon emission. In s o l i d s , t h i s e f f e c t i s normally associated with reactions occurring on the surface such as the oxidation of phosphorus and unsaturated s i l i c o n oxide. In semiconductors, l i g h t emission may follow e x c i t a t i o n by an externally applied e l e c t r i c f i e l d [27], The material i s normally e x c i t e d by a p p l y i n g an e l e c t r i c f i e l d to an e l e c t r o n i c s t a t e a few e l e c t r o n v o l t s above the ground state. Subsequent to excitation, there may be energy tran-sport to a radiating s i t e where relaxation by electrolumine-20 scent emission occurs. 1.6.2 MOLECULAR SOLIDS Organic molecules i n the s o l i d s t a t e may be c a l l e d molecular so l i d s since the s o l i d i s held together by van der Waals f o r c e s between the i n d i v i d u a l molecules. The weak interactions between in d i v i d u a l molecules i n the s o l i d state do not s i g n i f i c a n t l y a l t e r the e l e c t r o n i c s t r u c t u r e of in d i v i d u a l constituent molecules. Therefore, the lumines-cence i s s t i l l c h a r a c t e r i s t i c of the emitting molecule. The use of low temperature, r a r e gas matrix i s o l a t i o n of aromatic hydrocarbons [18] cl o s e l y approaches the ide a l environment of a low pressure gas with minimal interactions of a molecule with i t s environment. Rigid glass Shpol'skii m a trices [29] take advantage of dimensional and geometric correlations between a guest organic molecule and i t s host s o l v e n t i n the production of near l i n e l i k e luminescence spectra. Emission spectral perturbations due to the presence of neighbors are g e n e r a l l y minor i n magnitude; they may be produced by: Davydov s p l i t t i n g of energy states, changes i n the o p t i c a l and d i e l e c t r i c p r o p e r t i e s of the media, and exciton interactions. Excited state l i f e t i m e s are markedly dependent on the type of neighbor and i t s o r i e n t a t i o n and d i s t a n c e w i t h r e s p e c t t o the l u m i n e s c e n t m o l e c u l e . R a d i a t i o n l e s s processes i n organic s o l i d s [30], to a f i r s t approximation, tend to be l o c a l i z e d to eff e c t s between the luminescent molecule and i t s close neighbors. 21 1.6.3 SEMICONDUCTORS Semiconductors are s o l i d m a t e r i a l s whose constituent atoms are bonded with each other by covalent bonds, the outer e l e c t r o n o r b i t a l s of the c o n s t i t u e n t atoms overlap each other with the net r e s u l t that i t i s impossible to assign a p a r t i c u l a r electron with a p a r t i c u l a r atom. Since luminescence i s a f u n c t i o n of changes i n e l e c t r o n energy s t a t e s , luminescence from a semiconductor [31] i s h i g h l y dependent on the properties of the entire s o l i d material as well as the properties of i t s in d i v i d u a l constituents. This i s i n marked contrast to the behavior of molecular cr y s t a l s . To i l l u s t r a t e luminescence i n semiconductors, consider a t y p i c a l wide band gap III-V compound such as GaAs. At low temperatures, say around 4 K, and i n the dark, pure GaAs i s an insulator. If the compound remains at the same tempera-ture and i s exposed to l i g h t i t becomes conductive and i s luminescent with l i n e - l i k e and band emission i n the near i n f r a r e d . Now, consider the case where a specimen of GaAs doped with a small amount of s i l i c o n ("p-type") i s placed i n i n t i m a t e contact with a specimen of t e l l u r i u m doped GaAs ("n-type"). I f a s u f f i c i e n t l y high e l e c t r i c p o t e n t i a l i s applied across the material, i t w i l l luminesce and the lumi-nescence w i l l occur only at the p-n j u n c t i o n . In these examples, the luminescence observed i s due to electron-hole r a d i a t i v e recombination processes across the gap between conduction and valence bands i n GaAs. The r a d i a t i v e recombination processes i n semiconductors 22 w h e r e a n e l e c t r o n - h o l e p a i r was c r e a t e d b y p h o t o n a b s o r p t i o n a r e o u t l i n e d i n F i g u r e 1.3 [ 3 2 ] . T h e c o n d u c t i o n b a n d ( C B ) t o v a l e n c e b a n d ( V B ) t r a n s i t i o n s a r e t h e h i g h e s t e n e r g y t r a n s i t i o n s n o r m a l l y p o s s i b l e a n d a r e s e e n a t h i g h e r t e m p e -r a t u r e s ; a t l o w t e m p e r a t u r e s , t h i s t r a n s i t i o n i s l i n e l i k e . T h e e x c i t o n ( E ) t o V B t r a n s i t i o n s a r e s e e n o n l y a t l o w t e m p e r a t u r e s i n e x t r e m e l y p u r e m a t e r i a l s . T h e E t o V B t r a n s i t i o n s may b e d u e t o e i t h e r t h e d e c a y o f f r e e e x c i t o n s o r e x c i t o n s b o u n d t o i m p u r i t i e s . When i m p u r i t i e s a n d d e f e c t s a r e p r e s e n t i n t h e s e m i c o n -d u c t o r , e n e r g y l e v e l s w i t h i n t h e b a n d g a p may b e c r e a t e d . A d o n o r a t o m i s a n i m p u r i t y a t o m t h a t c a n r e a d i l y g i v e u p a n e l e c t r o n . When p r e s e n t i n a s e m i c o n d u c t o r a n d w h e n i o n i z e d , i t g i v e s u p a n e l e c t r o n t o t h e c o n d u c t i o n b a n d . T h u s , a d o n o r b o u n d e n e r g y l e v e l b e l o w t h e c o n d u c t i o n b a n d i s c r e a t e d . The d e p t h b e l o w t h e c o n d u c t i o n b a n d i s t e r m e d t h e d o n o r i o n i z a t i o n e n e r g y a n d i s a f u n c t i o n o f t h e c o m p o s i t i o n o f b o t h t h e s e m i c o n d u c t o r h o s t a n d d o p a n t a t o m g u e s t . I n a n a n a l o g o u s m a n n e r , a c c e p t o r s t a t e s ( h o l e s ) a r e f o r m e d w h e n a d o p a n t c a p a b l e o f a c c e p t i n g e l e c t r o n s i s p r e s e n t . T h e h o l e i s f r e e d w h e n t h e a c c e p t o r i s i o n i z e d . T h i s i n p u t o f e n e r g y i s r e p r e s e n t e d a s t h e a c c e p t o r b o u n d e n e r g y l e v e l a b o v e t h e v a l e n c e b a n d . R a d i a t i v e r e c o m b i n a t i o n p r o c e s s e s may a l s o t a k e p l a c e b e t w e e n CB a n d a c c e p t o r ( A ) o r d e e p a c c e p t o r ( D A ) l e v e l s . T h e d e p t h o f a c c e p t o r l e v e l s a r e a f u n c t i o n o f t h e c o m p o -s i t i o n o f t h e s e m i c o n d u c t o r m a t e r i a l . S i m i l a r l y , 23 E X C I T O N : ; ^ •M^.w::::;: :::::::::::::::: S:::::::::: >::D^»"cj iblftf:':::-5:::-:::-:-:::-;-:::-:: ^LVCS "0 W : : : : : : : : : : : : : : : : : : : : >:::::: mmm DEEP £iiA.C.CE.PT.PJR::v:v :iACCEPf'P'^ ;l::l::H::::::::::::::::::::::::; : DEEP {{{{{{{{•DONOR {{{ ^ • • J : DEEP :• {{{{{{{{•DONOR{ DEEP ^ACCEPTOR {{{{{AJCt^T!^^^ 1VALENCE BAND F i g u r e .1.3 L u m i n e s c e n c e a s s o c i a t e d e l e c t r o n - h o l e p a i r r e c o m b i n a t i o n p r o c e s s e s i n s e m i c o n d u c t o r s . 24 t r a n s i t i o n s m a y t a k e p l a c e b e t w e e n d o n o r (D) o r d e e p d o n o r (DD) l e v e l s a n d t h e V B . I n a d d i t i o n , r e c o m b i n a t i o n c a n o c c u r b e t w e e n t h e D o r DD l e v e l s a n d t h e A o r DA l e v e l s . I n p - n j u n c t i o n s , t h e r a d i a t i v e r e c o m b i n a t i o n p r o c e s s e s a r e s i m i l a r . T h e c h i e f d i f f e r e n c e i n t h i s s i t u a t i o n i s t h a t , i n s t e a d o f o p t i c a l l y p u m p i n g t h e m a t e r i a l , t h e c o n d u c t i o n b a n d e l e c t r o n s may b e pumped i n t o t h e p - r e g i o n b y f o r w a r d b i a s i n g t h e p - n j u n c t i o n w i t h a n a p p l i e d e l e c t r i c p o t e n t i a l . S i n c e t h e l u m i n e s c e n c e o r i g i n a t e s i n t h e j u n c t i o n r e g i o n , t h e a p p l i e d b i a s v o l t a g e i s a p p r o x i m a t e l y t h a t o f t h e b a n d g a p i t s e l f . The l u m i n e s c e n c e s p e c t r u m f r o m a s e m i c o n d u c t o r n o r m a l l y h a s a n a m o r p h o u s , n o n d e s c r i p t a p p e a r a n c e t h a t i s t h e r e s u l t o f a c o m p l e x m i x t u r e o f b r o a d a n d n a r r o w b a n d s s u p e r i m p o s e d o n e a c h o t h e r . T h u s , t h e a p p a r e n t l y f e a t u r e l e s s l u m i n e s -c e n c e s p e c t r u m c o n v e y s a t r e m e n d o u s a m o u n t o f i n f o r m a t i o n o n t h e h o s t s e m i c o n d u c t o r a n d i t s d o p a n t g u e s t s . F o r e x a m p l e , s t u d i e s o n t h e e f f e c t o f a p p l i e d b i a s p o t e n t i a l o n t h e l u m i n e s c e n c e s p e c t r u m m a y p r o v i d e i n s i g h t s o n t h e c o m p o s i t i o n o f a m a t e r i a l i n t h e v i c i n i t y o f t h e p - n j u n c t i o n . 1.6.4 I N O R G A N I C I N S U L A T O R S The t h i r d c l a s s o f l u m i n e s c e n t s o l i d m a t e r i a l s i s t h a t o f t h e i n o r g a n i c i n s u l a t o r s . T h i s g r o u p i n c l u d e s a l l n o n c o n d u c t i n g s o l i d s t h a t a r e n e i t h e r s e m i c o n d u c t o r s n o r o r g a n i c m o l e c u l e s , f o r e x a m p l e : n a t u r a l l y o c c u r r i n g r o c k s a n d m i n e r a l s , g e m s t o n e s , c e r a m i c s , g l a s s , a n d i n o r g a n i c 25 c o n s t r u c t i o n m a t e r i a l s . T h e c o m m o n f e a t u r e o f t h e s e s u b s t a n c e s i s t h a t l u m i n e s c e n c e f r o m t h e m i s a l m o s t i n e v i t a b l y a s s o c i a t e d w i t h i m p u r i t y a t o m s a n d d e f e c t s i n t h e i r c r y s t a l s t r u c t u r e , a l t h o u g h t h e r e a r e a f e w n o t a b l e e x c e p t i o n s t o t h i s g e n e r a l i z a t i o n . I n o r g a n i c i n s u l a t o r h o s t l a t t i c e s a r e t r a n s p a r e n t t o v i s i b l e l i g h t , h a v e l a r g e b a n d g a p s a n d h a v e b o n d i n g r a n g i n g f r o m c o v a l e n t ( d i a m o n d ) t o i o n i c ( C s F ) . Common h o s t l a t t i c e t y p e s i n c l u d e : 1 ) t h e a l k a l i m e t a l a n d a l k a l i n e e a r t h h a l i d e s , 2 ) o x y g e n d o m i n a t e d l a t t i c e s s u c h a s AI2O3, CaCC>3 a n d C a W 0 4 , 3 ) s o m e I I - I V c o m p o u n d s s u c h a s Z n S , 4) g l a s s , a n d 5) d i a m o n d . L u m i n e s c e n c e f r o m t h i s d i v e r s e g r o u p o f m a t e r i a l s i n v o l v e s s e v e r a l q u i t e d i f f e r e n t p r o c e s s e s , some o f w h i c h a r e c o n s i d e r e d i n t h e f o l l o w i n g s e c t i o n s . 1.6.4.1 THE COLOR CENTER I N A L K A L I H A L I D E S C o n s i d e r a p e r f e c t c r y s t a l o f p u r e s o d i u m c h l o r i d e , a s u b s t a n c e w h i c h i s n o r m a l l y t r a n s p a r e n t f r o m a b o u t 175 nm t o 1 4 5 0 0 n m . I f t h i s c r y s t a l i s e x p o s e d t o h i g h e n e r g y p h o t o n s s u c h a s X - r a y s [ 3 3 ] i t w i l l b e c o m e y e l l o w i n c o l o r a n d w i l l r e t a i n t h a t c o l o r a f t e r c e s s a t i o n o f t h e X - r a y i r r a d i a t i o n p r o v i d e d t h a t t h e c r y s t a l i s k e p t a t c r y o g e n i c c o n d i t i o n s . On e x p o s u r e t o v i s i b l e l i g h t t h e c o o l e d c r y s t a l w i l l e x h i b i t s t r o n g b r o a d b a n d l u m i n e s c e n c e i n t h e n e a r i n f r a r e d . Some o f d e f e c t s i n t h e c r y s t a l l a t t i c e p r o d u c e d b y t h e X - r a y b o m b a r d m e n t m a y b e c o l o r c e n t e r s [ 3 4 ] s u c h a s t h e F c e n t e r w h i c h c o n s i s t s o f a n a n i o n v a c a n c y i n w h i c h a s i n g l e e l e c t r o n i s t r a p p e d . I n a n F c e n t e r , t h e t r a p p e d e l e c t r o n 26 may be considered to be a p a r t i c l e i n a box with walls made up of the neighboring ions that inter a c t with the p a r t i c l e . The i o n neighbor o r b i t a l s w i l l o v e r l a p with those of the trapped e l e c t r o n r e s u l t i n g i n e l e c t r o n i c s t a t e s that are intimately coupled to the c r y s t a l l a t t i c e . Thus the absor-ption and luminescence spectra of an F center convey i n f o r -mation on the c r y s t a l l a t t i c e i n the neighborhood of the F center. The s p e c t r a a s s o c i a t e d with an F center c o n s i s t of s i n g l e broad a b s o r p t i o n and emission bands. Even though both absorption and emission t r a n s i t i o n s occur between the same two energy s t a t e s there i s a l a r g e Stokes' s h i f t between them. The band width f o r the ab s o r p t i o n and e m i s s i o n bands i s a f u n c t i o n of the n e i g h b o r i n g i o n s v i b r a t i o n a l motion. The Stokes' s h i f t i s a r e s u l t of the d i f f e r e n t e l e c t r o s t a t i c environments between the ground and e x c i t e d s t a t e s i n the F c e n t e r . On e x c i t a t i o n , the neighboring ions are suddenly i n a d i f f e r e n t e l e c t r o s t a t i c environment and they rapidly reposition themselves to a new minimum p o t e n t i a l energy arrangement. Subsequent to t h i s rearrangement, relaxation to the ground state may occur by either photon emission or radiationless deactivation. 1.6.4.2 TRIVALENT RARE EARTH IONS IN LANTHANUM CHLORIDE A p e r f e c t , pure c r y s t a l of LaCl3 w i l l not luminesce when e x c i t e d by a broadband source such as a Xenon f l a s h lamp. However, i f the same source i s used to excite a LaCl3 c r y s t a l doped with a t r i v a l e n t rare earth ion such as P r + 3 , 27 very weak luminescence w i l l be observed. The emission and absorption spectra of the doped c r y s t a l consist of a series of sharp l i n e s s i m i l a r i n appearance to that of an i s o l a t e d atom. In t r i v a l e n t rare earth doped luminescent substances, the spectral l i n e s originate from t r a n s i t i o n s wholly within the 4f manifold of the rare earth ion and are c h a r a c t e r i s t i c of energy l e v e l s w i t h i n that p a r t i c u l a r e l e c t r o n s h e l l . Since the 4f e l e c t r o n s are s h i e l d e d from the e x t e r n a l environment, the energy l e v e l s of the rare earth i o n are only s l i g h t l y perturbed by the c r y s t a l f i e l d of the host l a t t i c e . The perturbations i n the spectral l i n e s do r e f l e c t the d i f f e r e n t c r y s t a l f i e l d s of v a r i o u s host l a t t i c e s by minor s h i f t s i n wavelength and s p l i t t i n g s w i t h i n energy l e v e l s [35]. The t r a n s i t i o n s involved are e s s e n t i a l l y purely elec-t r o n i c with minimal d i r e c t i n t e r a c t i o n with host l a t t i c e v i b r a t i o n s . There i s no Stokes' s h i f t and consequently, thermal quenching [36] due to crossing of excited state and ground state parabolae does not occur. The p r i n c i p a l e f f e c t of temperature on emission and a b s o r p t i o n s p e c t r a i s band broadening, with quenching p r i m a r i l y due to electromagnetic c o u p l i n g and t u n n e l i n g e f f e c t s . Luminescence from a t r i v a l e n t r a r e e a r t h i o n may be perturbed by i m p u r i t i e s present i n the host l a t t i c e . These p e r t u r b a t i o n e f f e c t s were used by M i l l e r [37] to analyze f o r i m p u r i t i e s i n a host l a t t i c e . 28 1 . 6 . 5 THE CONFIGURATION COORDINATE MODEL T h e a b s o r p t i o n a n d e m i s s i o n s p e c t r a o f a l o c a l i z e d e x c i t a t i o n i n a n i n o r g a n i c i n s u l a t o r may be a p p r o x i m a t e d by a o n e d i m e n s i o n a l c o n f i g u r a t i o n c o o r d i n a t e m o d e l [ 3 8 - 4 1 ] . A l t h o u g h t h i s m o d e l i s v a l i d o n l y i f t h e e l e c t r o n - p h o n o n i n t e r a c t i o n i n v o l v e s o n e v i b r a t i o n a l m o d e i n t h e l a t t i c e , p r e d i c t i o n s f o r m o r e c o m p l e x s y s t e m s b a s e d o n t h i s m o d e l a g r e e f a v o r a b l y w i t h e x p e r i m e n t a l d a t a . A c o n f i g u r a t i o n c o o r d i n a t e m o d e l d i a g r a m f o r a l o c a l i z e d e x c i t a t i o n , s a y a d o p a n t i o n i n a h o s t l a t t i c e , i s s h o w n i n F i g u r e 1 . 4 . T h e v e r t i c a l a x i s r e p r e s e n t s s y s t e m e n e r g y , E , a n d t h e h o r i z o n t a l a x i s i s t h e c o n f i g u r a t i o n c o o r d i n a t e , Q , w h i c h r e p r e s e n t s t h e d i s t a n c e f r o m t h e d o p a n t i o n t o t h e n e a r e s t n e i g h b o r i o n s i n t h e l a t t i c e . T h e e q u i l i b r i u m v a l u e o f Q f o r t h e i o n i n i t s g r o u n d s t a t e i s z e r o . T h e p o t e n t i a l e n e r g y , E , a s a f u n c t i o n o f t h e c o n f i g u r a t i o n c o o r d i n a t e i s t h e n g i v e n b y : E g = i k G Q 2 ( 1 . 1 8 ) w h e r e k g i s t h e f o r c e c o n s t a n t f o r t h e g r o u n d s t a t e i o n . F o r t h e i o n i n t h e e x c i t e d s t a t e , t h e p o t e n t i a l e n e r g y f u n c t i o n i s E e = i k E ( Q - Q 0 ) 2 + E Q ( 1 . 1 9 ) w h e r e k e i s t h e f o r c e c o n s t a n t f o r t h e e x c i t e d s t a t e i o n , Q Q i s t h e e q u i l i b r i u m v a l u e f o r t h e i o n i n i t s e x c i t e d s t a t e , a n d E Q i s t h e e l e c t r o n i c e n e r g y d i f f e r e n c e b e t w e e n t h e 2 9 E t Figure 1.4 Configuration coordinate diagram f o r t r a n s i -tions between an excited state and the ground state. 30 excited and ground state equilibrium values. N e g l e c t i n g the zero p o i n t energies i n the ground and e x c i t e d s t a t e s , the band maxima f o r absorption, h v u a , and emission, hvg e are h v 0 a = E0 + SaJfiwe (1 .20) h v 0 e = E0 ~ se# wg (1.21) where S a and S e are the average number of phonons emitted afte r photon absorption and emission respectively; tfwe/ yitog, are the average phonon energies f o r the e x c i t e d and ground s t a t e s , respectively. For a d i p o l e t r a n s i t i o n , assuming t h a t both the sem i c l a s s i c a l approximation and the Franck-Condon p r i n c i p l e are followed, the emission band p r o f i l e i s described by the rel a t i o n s h i p : I(hv) = [ 6 4 T T 4 V 4 / 3C 3 ] G(hv) (1.22) where the term G(hv) i s the spectrum shape f u n c t i o n . The spectrum shape function i s : G(h v) = I weighted |M±f|2 (1.23) where the i n i t i a l s t a t e s i n the matrix element M^j are weighted by the appropriate Boltzmann factor. The spectrum shape f a c t o r i s Gaussian i n p r o f i l e and the r e s u l t i n g e mission p r o f i l e i s s l i g h t l y skewed due to the v 4 term i n equation (1.22). Since the emission s p e c t r a l p r o f i l e i s a Gaussian 31 shape, i t may be d e s c r i b e d i n terms of moments [42], The second moment (variance) at zero Kelvin i s : oj = S e ( K w g ) 3 / ( K a ) e ) (1.24) and has a temperature dependence: a e(T) = a e(0K) [tanh(Kwg/2kT)]~i (1.25) The a b s o r p t i o n s p e c t r a l p r o f i l e r e l a t i o n s h i p s f o l l o w an analogous argument. Skewness and peakedness [42] r e l a t i o n s h i p s have been derived. However, i n many simple luminescent systems, these higher terms are not required to describe the observed emission band shapes. 1.6.6 ENERGY TRANSFER When a reg i o n i n a s o l i d absorbs energy and becomes e l e c t r o n i c a l l y e x c i t e d , some or a l l of that energy may be t r a n s f e r r e d to another r e g i o n i n the s o l i d before the exc i t a t i o n energy i s radiated by the emission of photons or heat as i l l u s t r a t e d i n Figure 1.5. Energy transfer from one region to another i s dependent on the l o c a l environments of the s e n s i t i z e r and a c t i v a t o r s i t e s as w e l l as the propag-ation path between them. Luminescence from a substance i s h i g h l y dependent on energy t r a n s f e r phenomena and conveys information on the various energy transfer processes occur-r i n g i n the s o l i d . In s o l i d s , there are three fundamental mechanisms of energy transfer: charge transport, radiative, and nonradiative transfer. Charge transport, or photoconductivity, occurs when a 32 (^sensitizer (^activator (JOkiller site CD trap site »excitation ^^luminescence « K 5 ; »nonradiative transfer ffiphonon emission F i g u r e 1 .5 N o n r a d i a t i v e e n e r g y m o v e m e n t i n s o l i d s : ( a ) e n e r g y t r a n s f e r , ( b ) e n e r g y m i g r a t i o n , ( c ) c o n c e n t r a t i o n q u e n c h i n g w i t h t r a n s f e r t o k i l -l e r s i t e s , (d) t r a p s a n d d e l a y e d l u m i n e s c e n c e . 33 photon of s u f f i c i e n t energy i s absorbed i n the s o l i d and promotes an electron into the conduction band. This process i s important i n metals and semiconductors. However, i n most i n o r g a n i c i n s u l a t o r s , t h i s process i s not a s i g n i f i c a n t means of energy transport. The resonance rad i a t i v e transfer process occurs when a s e n s i t i z e r emits a photon which t r a v e l s through the s o l i d and i s subsequently absorbed by an a c t i v a t o r which i n turn luminesces. The d i s t i n g u i s h i n g f e a t u r e s a s s o c i a t e d with t h i s t r a n s f e r process are 1 ) the t r a n s f e r i s a f u n c t i o n of sample geometry, and 2) the s e n s i t i z e r l i f e t i m e i s independent of a c t i v a t o r c o n c e n t r a t i o n . However, the emission spectrum i s a function of activator concentration. The p r o b a b i l i t y for energy transfer between s e n s i t i z e r and a c t i v a t o r as a f u n c t i o n of the d i s t a n c e between them, P S A ( R ) ' * s given by the r e l a t i o n s h i p [43]: PSA = 0 - a / ( 4 T T R 2 T s ) /G s(v)G A(v)d v (1.26) where R i s the distance between s e n s i t i z e r and activator, a A i s the integrated activator absorption cross section, x s i s the s e n s i t i z e r l i f e t i m e , and the i n t e g r a l term represents the s p e c t r a l overlap between s e n s i t i z e r emission and a c t i v a t o r absorption. The t h i r d fundamental mechanism of energy transfer i n s o l i d s i s that of r a d i a t i o n l e s s energy t r a n s f e r where the b a s i c i n t e r a c t i o n i s e l e c t r o m a g n e t i c c o u p l i n g between an energy donor and an energy acceptor. This mechanism i s best 34 subdivided into two cases: resonance radiationless transfer and nonresonance rad i a t i o n l e s s transfer. In resonance radiationless energy transfer, the energy l e v e l s between energy donor and energy acceptor are overlap-ped and the t r a n s f e r i s s o l e l y by d i r e c t e l e c t r o m a g n e t i c coupling between donor and acceptor. A " v i r t u a l photon" may be considered to be the t r a n s f e r agent. The b a s i c quantum mechanical t h e o r e t i c a l treatment was done by F o r s t e r [44] f o r the case of d i p o l e - d i p o l e i n t e r a c t i o n s between s o l i d organic molecules. This transfer mode i s an additional path f o r s e n s i t i z e r d e e x c i t a t i o n . Consequently, a decrease i n se n s i t i z e r l i f e t i m e that i s proportional to activator conce-ntration i s c h a r a c t e r i s t i c of t h i s mode of energy transfer. A q u a n t i t a t i v e treatment f o r resonance r a d i a t i o n l e s s energy t r a n s f e r has been summarized by Powell and Blasse [45], For a d i p o l e - d i p o l e i n t e r a c t i o n between s e n s i t i z e r and activator, the overlap i n t e g r a l may be s i m p l i f i e d to the form: Q = /g s(v)G a(v)dv (1.27) where the g s and G a terms are the normalized spectral band-shape f u n c t i o n s f o r the square of the o r i e n t a t i o n angle between the s e n s i t i z e r and activator dipoles. The c r i t i c a l i n t e r a c t i o n d i s t a n c e ( R o > / t h e d i s t a n c e a t which the t r a n s f e r r a t e i s equal to the i n t r i n s i c s e n s i t i z e r decay rate, i s defined as: R 0 = { [3f ae 2fi<J> s]/[4(2rrnv s a) 4mc 2]}1/ 6 (1.28) 35 where f a i s the activator o s c i l l a t o r strength, e i s electron charge, <J>S i s the s e n s i t i z e r quantum e f f i c i e n c y , n i s the host l a t t i c e r e f r a c t i v e index, v s a i s the average value for the wave number i n the s p e c t r a l overlap region, m i s e l e c -tron mass, and c i s the speed of l i g h t . Thus, for any given s e n s i t i z e r - a c t i v a t o r p a i r the d i p o l e - d i p o l e i n t e r a c t i o n energy transfer rate between them i s given by w s a - ( T g ) - 1 ( R 0 / R s a ) 6 (1.29) where i s the i n t r i n s i c s e n s i t i z e r l i f e t i m e and R s a i s the d i s t a n c e between s e n s i t i z e r and a c t i v a t o r . The t r a n s f e r rates for dipole-quadrupole and quadrupole-quadrupole i n t e r -actions are analogous, with the exponential factors of 8 and 10 respectively. In nonresonance r a d i a t i o n l e s s energy t r a n s f e r , the donor and acceptor energy lev e l s do not overlap. The energy l e v e l match and subsequent t r a n s f e r i s made p o s s i b l e by creation or destruction of phonons i n the host l a t t i c e . The transfer rate i s dependent on the overlap i n t e g r a l which i n turn i s dependent on the d i s t r i b u t i o n of phonons present. The quantitative treatment of nonresonance radiation-l e s s energy t r a n s f e r , as summarized by Powell and Blasse [45], provides the background for the equations that follow. In a s o l i d the temperature dependent occupation number for phonons of p o l a r i z a t i o n j and wave vector k, n j j ^ ±s given by the relationship: n j k = 1/[exp(AE s a/kT)-1 ] (1.30) 36 where A E s a i s the energy difference between s e n s i t i z e r and activator energy l e v e l s , k i s Boltzmann's constant, and T i s temperature i n K e l v i n . For phonon absorption, the phonon population number i s given as n^n-j^; for phonon emission, the phonon population number i s given as n e = n j k + 1 * There are two l i m i t i n g cases for phonon assisted energy t r a n s f e r : the f i r s t where the phonon wavelength i s very l a r g e with r e s p e c t to s e n s i t i z e r - a c t i v a t o r s e p a r a t i o n and the second where the phonon wavelength i s much shorter than the distance between s e n s i t i z e r and activator. In the case where the phonon wavelength i s greater than the d i s t a n c e between s e n s i t i z e r and a c t i v a t o r , the energy transfer rate i s given by 0 ) s a = [ ( D | A E s a | 3 R s a ) / 6 J f i 2 ] ^ n p ( a j / v ] ) (1.31) where A E s a i s the energy l e v e l difference between s e n s i t i z e r and a c t i v a t o r , R s a i s the d i s t a n c e between s e n s i t i z e r and activator, H i s Planck's constant, n p ± s the phonon popula-t i o n number ( n e f o r emission or n a f o r absorption), aj i s the angular average of the l a t t i c e s t r a i n parameter, V J i s the phonon vel o c i t y , and D i s a constant term defined as D = [J 2(f-g) 2]/TrK 4p (1.32) where J i s a quantum mechanical matrix element f o r the system independent of phonon state. The parameters f and g are c o u p l i n g constants f o r the ground and e x c i t e d s t a t e s r e s p e c t i v e l y ( t h e i r d i f f e r e n c e i s assumed to be equal f o r 37 s e n s i t i z e r a n d a c t i v a t o r ) , a n d p i s t h e h o s t l a t t i c e d e n s i t y . I n t h e c a s e w h e r e t h e p h o n o n w a v e l e n g t h i s s h o r t e r t h a n t h e d i s t a n c e b e t w e e n s e n s i t i z e r a n d a c t i v a t o r t h e e n e r g y t r a n s f e r r a t e i s g i v e n a s I n c o m p a r i n g t h e b e h a v i o r d e s c r i b e d b y e q u a t i o n s ( 1 . 3 1 ) a n d ( 1 . 3 3 ) , t h e i m p o r t a n t p o i n t s a r e t h a t f o r b o t h c a s e s t h e t e m p e r a t u r e d e p e n d e n c i e s a r e s i m i l a r . H o w e v e r , t h e e n e r g y t r a n s f e r r a t e i s m a r k e d l y d e p e n d e n t o n t h e d i f f e r e n c e s i n e n e r g y l e v e l s b e t w e e n s e n s i t i z e r a n d a c t i v a t o r . O n l y t h e m o s t s a l i e n t p o i n t s o f e n e r g y t r a n s f e r i n s o l i d s h a v e b e e n c o n s i d e r e d i n t h i s d i s c u s s i o n . I n d e p t h t r e a t m e n t s o f t h i s c o m p l e x t o p i c a r e g i v e n i n r e f e r e n c e s [ 4 6 - 4 9 ] . 1.6.7 ENERGY M I G R A T I O N E n e r g y m i g r a t i o n i s a m u l t i s t e p p r o c e s s c o n s i s t i n g o f a s e r i e s o f e n e r g y t r a n s f e r s t e p s f r o m o n e s e n s i t i z e r t o a n o t h e r , w i t h e a c h s t e p i n t h i s c a s c a d e o c c u r r i n g b y a n y o f t h e t h r e e b a s i c e n e r g y t r a n s f e r m e c h a n i s m s . The r e s u l t i n g c o m p l e x b e h a v i o r e f f e c t i v e l y p r e c l u d e s a t t e m p t s t o f o r m u l a t e a g e n e r a l t h e o r e t i c a l e x p r e s s i o n a p p l i c a b l e t o a l l p h y s i c a l c a s e s . M o d e l s b a s e d o n e x c i t o n m o t i o n [ 5 0 ] h a v e b e e n s u c c e s s f u l i n e x p l a i n i n g e n e r g y m i g r a t i o n i n f l u e n c e d l u m i n e -s c e n c e d e c a y k i n e t i c s f o u n d i n s e l e c t e d c a s e s . I n r e a l s o l i d s , t h e s e n s i t i z e r - s e n s i t i z e r e n e r g y ( 1 . 3 3 ) 38 migration chain may terminate by energy transfer to a trap or k i l l e r s i t e before an activator s i t e i s encountered, as i l l u s t r a t e d i n Figure 1.5. When energy i s transferred from a s e n s i t i z e r to a k i l l e r s i t e , i n t e r n a l processes occur that convert a l l t r a n s f e r r e d energy to phonons, the net r e s u l t of which i s a quenching of l u m i n e s c e n c e . Traps are metastable states i n a l a t t i c e . They may be either a l e v e l with a very low t r a n s i t i o n p r o b a b i l i t y f o r spontaneous emission or a defect s i t e where an electron can be captured and remain for a s i g n i f i c a n t time before recombination. The end r e s u l t of energy t r a n s f e r to a tra p i s the long l i f e t i m e luminescence that i s c h a r a c t e r i s t i c of the trap s i t e . If a s o l i d material i s excited by a pulsed source such as a nitrogen laser pumped dye laser, the luminescence decay k i n e t i c s may be modeled f o r the two extreme cases of s e n s i t i z e r - s e n s i t i z e r energy migration [36,51]. The f i r s t case i s that of fast d i f f u s i o n among se n s i t i z e r s i.e., where the p r o b a b i l i t y for energy transfer between se n s i t i z e r s i s much gr e a t e r than that f o r energy t r a n s f e r between a s e n s i t i z e r and Z, which i s a t r a p or k i l l e r s i t e . In t h i s case, the emission i n t e n s i t y , I, may be described by the rel a t i o n s h i p [36]: I = I 0 e x p ( - t / x ) e x p ( - C z P S 2 t ) (1.34) where T i s the i n t r i n s i c l i f e t i m e of the emitting species, C z i s the concentration of species Z, P s z i s t h e probability f o r the energy t r a n s f e r from the s e n s i t i z e r to species Z, 39 a n d t i s t i m e . The o v e r a l l r e s u l t i s t h a t t h e d e c a y r a t e i s a n e x p o n e n t i a l f u n c t i o n a n d i s d e t e r m i n e d b y t h e c o n c e n t r a -t i o n o f t r a p p i n g o r k i l l e r s p e c i e s Z . T h e s e c o n d l i m i t i n g c a s e i s t h a t o f d i f f u s i o n l i m i t e d e n e r g y m i g r a t i o n w h e r e t h e p r o b a b i l i t y o f e n e r g y t r a n s f e r b e t w e e n s e n s i t i z e r s i s m u c h l e s s t h a t t h a t b e t w e e n a s e n s i t i z e r a n d s p e c i e s Z . I n t h i s c a s e , t h e r e l a t i v e l y s l o w s e n s i t i z e r - s e n s i t i z e r e n e r g y m i g r a t i o n may p r o c e e d t h r o u g h t h e l a t t i c e a l o n g o n e , t w o , o r t h r e e d i m e n s i o n a l p a t h w a y s u n t i l t h e m i g r a t i o n i s t e r m i n a t e d b y e n e r g y t r a n s f e r t o s p e c i e s Z . I n t e n s i t y r e l a t i o n s h i p s f o r t h e s e p a t h w a y s f o r t h e l i m i t i n g s i t u a t i o n w h e r e t->-°° a r e a s f o l l o w s . I n a o n e d i m e n s i o n a l s y s t e m , t h e i n t e n s i t y r e l a t i o n s h i p i s [ 5 1 , 5 2 ] g i v e n a s I = I 0 e x p ( - t / T ) e x p [ - 3 ( 7 r 2 C z p s s t / 4 ) 1 / 3 J ( 1 . 3 5 ) w h e r e P g s i s t h e p r o b a b i l i t y o f t h e s e n s i t i z e r - s e n s i t i z e r e n e r g y t r a n s f e r p r o c e s s . T h e r e s u l t o f e n e r g y m i g r a t i o n b y t h i s p a t h w a y i s t h a t t h e d e c a y c u r v e i s n o n e x p o n e n t i a l . F o r e n e r g y m i g r a t i o n b y a t w o d i m e n s i o n a l p a t h w a y [ 3 6 ] : I = I 0 e x p ( - t / T ) / ( 4 T T C z Z - 2 D t ) ( 1 . 3 6 ) w h e r e Z i s t h e t r a p p i n g r a d i u s f o r s p e c i e s Z , a n d D i s t h e d i f f u s i o n c o n s t a n t f o r t h e e x c i t a t i o n e n e r g y m i g r a t i o n among t h e s e n s i t i z e r s . H e r e , a s i n t h e o n e d i m e n s i o n c a s e , t h e d e c a y c u r v e i s n o n e x p o n e n t i a l . I n m o s t s i t u a t i o n s , t h e e n e r g y m i g r a t i o n t a k e s a r a n d o m t h r e e d i m e n s i o n a l p a t h 40 t h r o u g h t h e l a t t i c e . I n t h i s c a s e , t h e i n t e n s i t y r e l a t i o n s h i p i s [ 3 6 , 5 1 , 5 3 ] g i v e n a s I = I 0 e x p ( - t / T ) e x p ( - 1 1 . 4 0 4 C z C l / 4 D 3 / 4 t ) ( 1 . 3 7 ) w h e r e C i s a n i n t e r a c t i o n p a r a m e t e r f o r t h e e n e r g y t r a n s f e r f r o m s e n s i t i z e r t o s p e c i e s Z . E n e r g y m i g r a t i o n i s r e s p o n s i b l e f o r c o n c e n t r a t i o n q u e n c h i n g e f f e c t s [ 5 1 , 5 4 , 5 5 ] i n s o l i d s . I t i s a n i m p o r t a n t p r o c e s s i n l a n t h a n i d e d o p e d m a t e r i a l s d u e t o t h e n a r r o w s p e c t r a l b a n d s o f t h e i n t r a f o r b i t a l t r a n s i t i o n s a n d t h e r e l a t i v e l y s m a l l p e r t u r b a t i o n s i n d u c e d b y t h e h o s t l a t t i c e . A n i m p o r t a n t c o n s e q u e n c e o f s l o w d i f f u s i o n e n e r g y m i g r a t i o n i s t h a t q u e n c h i n g a n d d e c a y k i n e t i c s a r e a f u n c t i o n o f b o t h c r y s t a l s i z e a n d t r a n s f e r g e o m e t r y w i t h i n t h e h o s t l a t t i c e . 1 .7 L U M I N E S C E N C E I N A N A L Y T I C A L C H E M I S T R Y L u m i n e s c e n c e s p e c t r o s c o p y i s a v e r y u s e f u l a n d p o w e r f u l t e c h n i q u e f o r c h e m i c a l a n a l y s i s a s i t i s i n h e r e n t l y a n o n d e s t r u c t i v e p r o c e s s w e l l s u i t e d f o r r e m o t e a n a l y s i s . L u m i n e s c e n c e d e t e c t i o n i s s e n s i t i v e , h a s w i d e d y n a m i c r a n g e , a n d i s r e a d i l y a p p l i e d a t a n y s t a g e i n t h e a n a l y t i c a l p r o t o c o l . T h e u l t i m a t e d e t e c t i o n l i m i t , t h e d e t e c t i o n a n d i d e n t i f i c a t i o n o f a s i n g l e i o n [ 5 6 ] h a s b e e n a c h i e v e d u s i n g l u m i n e s c e n c e s p e c t r o s c o p y . N g u y e n e t a l . [ 5 7 ] h a v e r e p o r t e d a d e t e c t i o n l i m i t o f a s i n g l e s p e c i e s c o n t a i n i n g t h e e q u i v a l e n t o f e i g h t R h o d a m i n e 6G f l u o r o p h o r e s u s i n g l a s e r -i n d u c e d f l u o r e s c e n c e d e t e c t i o n . D e s p i t e t h e s e a t t r i b u t e s , l u m i n e s c e n c e s p e c t r o s c o p y h a s 41 been considered [6] to be a l e s s d e s i r a b l e a n a l y t i c a l technique due to an apparent lack of s p e c i f i c i t y and a high s u s c e p t i b i l i t y to quenching and enhancement i n t e r f e r e n c e e f f e c t s . Stokes [12] noted the e f f e c t s of chemical environ-ment on luminescence from aqueous quinine solutions. E a r l y a n a l y t i c a l uses of luminescence were p r i m a r i l y q u a l i t a t i v e and empirical [58,59] with the p r i n c i p a l a p p l i -cations being i n forensic science, mineralogy, pharmaceuti-cals, and food analysis. One of the f i r s t published uses i n q u a n t i t a t i v e a n a l y s i s was by King [60] i n enhancing the s e n s i t i v i t y of the G u t z e i t t e s t f o r t r a c e a r s e n i c . Most early a n a l y t i c a l work was done using mercury discharge lamps as an e x c i t a t i o n source; g e n e r a l l y , t o t a l emission was recorded with minimal e f f o r t s to do measurements on narrow spectral regions. In c u r r e n t a n a l y t i c a l p r a c t i c e , luminescence based methods are applied primarily to l i q u i d solutions of organic molecules [61-63]. Inorganic a n a l y s i s by luminescence i s normally done on l i q u i d samples using luminescent organic complexes [61] and flame (plasma) atomic fluorescence [64]. The a n a l y s i s of i n o r g a n i c s o l i d s by luminescence spe c t r o -scopy has been l i m i t e d mainly to microscopy [65] and s i t u a -t i o n s where the a n a l y t e has been i n c o r p o r a t e d i n t o a host l a t t i c e such as i n the determination of trace quantities of uranium [66,67] or heavy metals [68], Luminescence from an i n o r g a n i c s o l i d i s i n h e r e n t l y a r i c h source of information on e l e c t r o n i c processes occurring 42 i n the m a t e r i a l . A consequence of t h i s high i n f o r m a t i o n content i s that single parameter luminescence measurements may have l i t t l e , i f any, d i r e c t r e l a t i o n s h i p to a given a t t r i b u t e of a luminescent s o l i d . An i n c r e a s e i n the luminescence measurement dimensionality affords an increased u t i l i z a t i o n of i n f o r m a t i o n c a r r i e d by the luminescence signal. The multidimensional approach has been successful i n the a n a l y s i s of i n d i v i d u a l components [69] present i n s o l i d mixtures of polynuclear aromatic hydrocarbons using a phosphorescence excitation-emission matrix method. Few reports on the analysis of inorganic s o l i d s i n s i t u by luminescence spectroscopy have appeared i n the recent l i t e r a t u r e . This i s l i k e l y due to a combination of the complex processes occurring i n inorganic s o l i d s and the use of s i n g l e parameter measurements. A m u l t i d i m e n s i o n a l approach to measuring luminescence may y i e l d a d i r e c t correspondence between a measured parameter and a p a r t i c u l a r a t t r i b u t e of the s o l i d . The emission and absorption spectra should be c h a r a c t e r i s t i c of the a c t i v a t o r and s e n s i t i z e r s p e c i e s i n the s o l i d . The decay time behavior c a r r i e s i n f o r m a t i o n on the environment of the s e n s i t i z e r s and a c t i v a t o r s , p a r t i c u l a r l y energy t r a n s f e r and energy migration processes occurring i n the s o l i d . In t h i s thesis, the multidimensional approach of time-wavelength resolved luminescence spectroscopy i s examined to see i f i t may be applied to chemical analysis of some simple luminescent inorganic soli d s . 43 C h a p t e r 2 E X P E R I M E N T A L 2 . 1 OVERVIEW T h i s c h a p t e r d e s c r i b e s t h e c o n s t r u c t i o n a n d o p e r a t i n g c h a r a c t e r i s t i c s o f t h e t i m e - w a v e l e n g t h r e s o l v e d l u m i n e s c e n c e s p e c t r o m e t e r a s w e l l a s t h e p r e p a r a t i o n o f c o m p o u n d s u s e d i n t h i s " s t u d y . 2 .2 SPECTROMETER A c o m p u t e r c o n t r o l l e d t i m e - w a v e l e n g t h r e s o l v e d l u m i n e s -c e n c e s p e c t r o m e t e r w a s c o n s t r u c t e d . A b l o c k , d i a g r a m o f t h e i n s t r u m e n t i s s h o w n i n F i g u r e 2 . 1 . T h e s p e c t r o m e t e r h a s w a v e l e n g t h c o v e r a g e o f 2 5 0 nm t o 7 0 0 nm a n d i s c a p a b l e o f m e a s u r i n g d e c a y l i f e t i m e s f r o m 100 n s t o 0.1 s 2 .2 .1 COMPUTER S Y S T E M A C o r o n a M o d e l P C 4 0 0 - H D 2 c o m p u t e r w i t h 10 m e g a b y t e h a r d d i s c ( C o r o n a D a t a S y s t e m s I n c . , T h o u s a n d O a k s , C A ) , R o l a n d M o d e l C C - 1 2 1 c o l o r m o n i t o r ( R o l a n d C o r p U S , L o s A n g e l e s , CA) a n d S T B G R A P H I X P L U S I I v i d e o b o a r d ( S T B S y s t e m s I n c . , R i c h a r d s o n , T X ) w a s u s e d t o c o n t r o l a n d a c q u i r e d a t a f r o m t h e s p e c t r o m e t e r . C o m m u n i c a t i o n s w i t h a n d c o n t r o l o f t h e s p e c t r o m e t e r c o m p o n e n t s w e r e d o n e t h r o u g h t h e s y s t e m s e r i a l a n d p a r a l l e l p o r t s . 2 . 2 . 2 SOFTWARE T h e i n s t r u m e n t c o n t r o l a n d d a t a a c q u i s i t i o n s o f t w a r e was w r i t t e n i n B A S I C . The p r o g r a m i s l i s t e d i n A p p e n d i x 1. T h e g r a p h i c s s o f t w a r e E n e r G r a p h i c s V e r s i o n 1.3 ( E n e r t r o n i c s R e s e a r c h I n c . , S t . L o u i s MO) w a s u s e d f o r t h e d i s p l a y o f 44 EXCIMER LASER CORONA COMPUTER PARALLEL PORT SERIAL PORT > SAMPLE REFERENCE PMT .35 METER MONOCHROMATOR i ISOLATION RELAY T R955 PMT SCAN CONTROLLER TRIGGER PHOTODIODE SR250 BOXCAR T i SR245 INTERFACE J + + PEAK DETECTOR F i g u r e 2.1 B l o c k d i a g r a m o f t h e t i m e - w a v e l e n g t h r e s o l v e d l u m i n e s c e n c e s p e c t r o m e t e r . 45 s p e c t r a . A m a j o r l i m i t a t i o n o f E n e r G r a p h i c s i s t h a t t h e p r o g r a m r e q u i r e s e q u a l s p a c i n g o f d a t a o n t h e x a n d y a x e s . 2 . 2 . 3 E X C I T A T I O N SOURCE A L u m o n i c s M o d e l T E - 8 6 1 T - 3 e x c i m e r l a s e r ( L u m o n i c s I n c . , K a n a t a , O n t . ) w i t h m a g n e s i u m f l u o r i d e o p t i c s w a s u s e d t o e x c i t e s a m p l e m a t e r i a l s . E x c i t a t i o n a t 193 nm a n d 248 nm w a s d o n e u s i n g A r F a n d K r F g a s m i x t u r e s r e s p e c t i v e l y . S t a n d a r d o p e r a t i n g c o n d i t i o n s r e c o m m e n d e d b y t h e m a n u f a -c t u r e r w e r e u s e d a s t h e y w e r e f o u n d t o p r o v i d e t h e m a x i m u m f i l l g a s l i f e t i m e s w i t h m i n i m a l p u l s e t o p u l s e v a r i a t i o n s i n o u t p u t beam i n t e n s i t y . L a s e r p e r f o r m a n c e w a s m a r k e d l y d e p e n d e n t o n t h e g a s m i x t u r e u s e d a n d r e c e n t u s e h i s t o r y [ 7 0 , 7 1 ] , F o r o p t i m a l f i l l g a s l i f e t i m e s a n d u n i f o r m p u l s e e n e r g i e s , t h e l a s e r h a d t o b e r u n s e v e r a l h o u r s e v e r y d a y , s e v e n d a y s a w e e k . P e r f o r m a n c e w a s r e d u c e d s i g n i f i c a n t l y b y e v e n a t w o d a y h i a t u s i n o p e r a t i o n . I f t h e u n i t was i d l e f o r m o r e t h a n o n e w e e k i t w o u l d t a k e s e v e r a l d a y s a n d n u m e r o u s g a s f i l l s t o r e g a i n a c c e p t a b l e p e r f o r m a n c e . A l l g a s e s u s e d f o r K r F o p e r a t i o n w e r e r e s e a r c h g r a d e . F o r A r F o p e r a t i o n , p r e p u r i f i e d g r a d e h e l i u m was s u b s t i t u t e d f o r e c o n o m y . F o r A r F o p e r a t i o n t h e p u l s e - t o - p u l s e r e p r o d u c i b i l i t y w a s b e t t e r t h a n ± 3% r e l a t i v e s t a n d a r d d e v i a t i o n ( R S D ) , w i t h a n i n i t i a l p u l s e e n e r g y o f a p p r o x i m a t e l y 100 m J a n d a u s e f u l g a s f i l l l i f e t i m e o f a b o u t f o u r h o u r s . F o r K r F o p e r a t i o n t h e p u l s e - t o - p u l s e r e p r o d u c i b i l i t y was b e t t e r t h a n ± 1 % RSD w i t h a n i n i t i a l p u l s e e n e r g y o f a b o u t 2 0 0 m J a n d a u s e f u l 46 gas f i l l l i f e t i m e of about 15 hours. The gas f i l l was considered spent when pulse energy dropped to l e s s than about 2 mJ with pulse-to-pulse r e p r o d u c i b i l i t y greater than ± 10% RSD. Short and long term changes i n laser output encountered during the measurement of a t y p i c a l spectrum using ArF e x c i t a t i o n are i l l u s t r a t e d i n Figure 2.2. In t e n s i t i e s have been normalized to the maximum pulse energy observed i n a given run. Every tenth pulse i s plotted. Run A was done on a f r e s h gas f i l l ; run B was done toward the end of the gas f i l l ' s u s e f u l l i f e . The data shown i n F i g u r e 2.2 were taken i n t h i s project's e a r l i e r stages before the operating parameters were optimized. Serious problems were encountered i n i n i t i a l attempts to use ArF. Laser operation was unstable with high voltage arcing and spurious radio frequency emissions strong enough to lock up both the computer system and interface module, as well as r a i s i n g havoc with other experiments being ca r r i e d out i n the laboratory. Stable laser operation with ArF was achieved only a f t e r modifying the t h y r a t r o n c i r c u i t by adding component RV4, a V420PA40A v a r i s t o r as shown i n F i g u r e 2.3. 2.2.4 LASER PULSE ENERGY MONITOR Laser pulse energy was monitored with a photomultiplier tube (PMT) and a peak d e t e c t o r c i r c u i t . The r e f e r e n c e PMT housing i s shown i n F i g u r e 2.4. The d e t e c t o r used was a 1P28 PMT with base wired f o r f a s t response [72,73] and 4 7 Figure 2.2 Excimer laser power output fluctuations, time s c a l e i s shot number -5-10; at 3 Hz: (A) f r e s h f i l l gas, (B) same f i l l gas three hours lat e r . 48 CM CO i > O o LU F i g u r e 2 . 3 M o d i f i c a t i o n t o l a s e r t h y r a t r o n c i r c u i t . 49 55 mm See inset 155 mm 15 mm 4 >\ 140 mm -•I D 5 mm I.D. U4T Pyrex disc, 22 H 1.6 mm Calcium tungstate powder Quartz disc, 22 x 1.6 mm Figure 2 . 4 Reference PMT housing. 50 terminated with a 50 Q load. A Kepco Model ABC 1 500M high voltage power supply (Kepco Inc., Flushing, NY) was used for the PMT. The screen c o n s i s t s of a t h i n l a y e r of calcium tungstate powder sandwiched between quartz and pyrex discs. The screen serves three functions: 1) i t e f f e c t i v e l y blocks out ambient room l i g h t , 2) i t converts laser UV radiation to v i s i b l e , and 3) i t protects the PMT from d i r e c t exposure to laser radiation. The peak d e t e c t o r c i r c u i t used i s shown i n F i g u r e 2.5. The c i r c u i t i s b u i l t around a Burr-Brown 4085KG peak detector module (Burr-Brown Corp., Tucson, AZ) with external buffer amplifiers and l o g i c gates to protect the module and provide additional signal control. 2.2.5 SAMPLE HOLDERS Two types of sample holders were used f o r powder specimens. In i n i t i a l work, sample powders were held i n 50 mm long test tubes made from 7 mm outer diameter by 1 mm w a l l quartz tubing. The t e s t tubes gave o f f s i g n i f i c a n t luminescence i n the UV and v i s i b l e regions. Despite the f a c t that a l l t e s t tubes were f a b r i c a t e d from the same l o t of tubing, the time-wavelength resolved luminescence spectra of the t e s t tubes was not u n i f o r m and t h e i r use was abandoned. In l a t e r work, sample powders were sandwiched between two 22 mm diameter by 1.6 mm t h i c k s u p r a s i l d i s c s (Amersil Inc., H i l l s i d e , NJ). The su p r a s i l discs exhibited f a i n t luminescence, with uniform time-wavelength resolved spectra for the d i f f e r e n t discs used. 51 en to c n to on nj (D * Cb (D rt n> o <r o n o H" H o e H-f t a (U ua n 3 +I5V -I5V 5V INPUT]__-I5V OUTPUT - ""•-PMT PEAK DETEC" roR owo MT NO 452 (WJI-"-—-••ij DATE | MIN.T MAR86| M C BY 1 ton f> Blades MM NO 2 . 2 . 6 SPECTROMETER O P T I C S T h e s p e c t r o m e t e r o p t i c a l a r r a n g e m e n t i s s h o w n i n F i g u r e 2 . 6 . T h e s a m p l e h o l d e r a n d q u a r t z c o l l e c t i o n l e n s e s w e r e m o u n t e d o n a n o p t i c a l r a i l . The o p t i c a l r a i l a n d m o n o c h r o -m a t o r w e r e m o u n t e d o n a n a l u m i n u m p l a t e f o r a l i g n m e n t s t a b i l i t y . A UV c u t o f f f i l t e r c o n s i s t i n g o f a 1 cm q u a r t z c e l l f i l l e d w i t h e i t h e r m e t h a n o l o r c a r b o n t e t r a c h l o r i d e was p l a c e d i n f r o n t o f t h e m o n o c h r o m a t o r e n t r a n c e s l i t s t o p r e v e n t s c a t t e r e d l a s e r r a d i a t i o n e n t e r i n g t h e m o n o c h r o -m a t o r . I n e a r l y w o r k a p y r e x d i s c w a s u s e d f o r a c u t o f f f i l t e r . H o w e v e r , t h i s d i s c was f o u n d t o l u m i n e s c e i n t e n s e l y f r o m s c a t t e r e d l a s e r r a d i a t i o n a n d i t s u s e was d i s c o n t i n u e d . A G C A / M c P h e r s o n M o d e l 2 7 0 m o n o c h r o m a t o r w i t h a M o d e l 7 0 0 - 5 1 s c a n c o n t r o l l e r ( M c P h e r s o n D i v i s i o n , S . I . C o r p . , A c t o n , MA) a l o n g w i t h a 1200 l i n e / m m h o l o g r a p h i c d i f f r a c t i o n g r a t i n g h a v i n g p e a k e f f i c i e n c y a t 500 nm w e r e u s e d . 2 . 2 . 7 WAVELENGTH SCANNING T h e M o d e l 7 0 0 - 5 1 s c a n c o n t r o l l e r w a s h i g h l y s u s c e p t i b l e t o e l e c t r o m a g n e t i c i n t e r f e r e n c e ( E M I ) f r o m t h e e x c i m e r l a s e r a s w e l l a s o t h e r l a b o r a t o r y n o i s e s o u r c e s . T o e l i m i n a t e s p u r i o u s c h a n g e s i n w a v e l e n g t h a n d s c a n d i r e c t i o n c a u s e d b y E M I , a l l e l e c t r i c a l l i n e s b e t w e e n t h e s c a n c o n t r o l l e r a n d m o n o c h r o m a t o r w e r e c o n n e c t e d b y a n i s o l a t i o n r e l a y o n l y when s c a n n i n g w a v e l e n g t h . T h e i s o l a t i o n r e l a y w a s c o n t r o l l e d b y t o g g l i n g a l i n e o n t h e C o r o n a p a r a l l e l p r i n t e r p o r t . W a v e l e n g t h s c a n n i n g w a s a c c o m p l i s h e d b y c o n n e c t i n g a s e c o n d l i n e o n t h e C o r o n a p a r a l l e l p o r t t o t h e e x t e r n a l 53 o s c i l l a t o r i n p u t o f t h e M o d e l 7 0 0 - 5 1 s c a n c o n t r o l l e r . T h e m a c h i n e l a n g u a g e r o u t i n e l i s t e d i n A p p e n d i x 2 w a s u s e d t o t o g g l e t h e p a r a l l e l p o r t l i n e a t a b o u t 6 0 0 H z f o r a n a p p r o p r i a t e n u m b e r o f p u l s e s t o s c a n f r o m o n e w a v e l e n g t h t o a n o t h e r . 2 . 2 . 8 D E T E C T O R S a m p l e l u m i n e s c e n c e w a s d e t e c t e d w i t h a H a m a m a t s u R 9 5 5 P M T ( H a m a m a t s u C o r p . , B r i d g e w a t e r , N J ) m o u n t e d i n a M c P h e r s o n M o d e l E U - 7 0 1 - 9 3 PMT h o u s i n g . T h e PMT s o c k e t was w i r e d f o r f a s t r e s p o n s e u s i n g t h e b a s e c i r c u i t d e s c r i b e d b y H a r r i s [ 7 2 ] , a n d a 5 0 o, l o a d r e s i s t o r w a s u s e d f o r t e r m i n a t i o n . H i g h v o l t a g e p o w e r s u p p l i e s u s e d w e r e a F l u k e M o d e l 4 1 3 C ( J o h n F l u k e M f g . C o . I n c . , S e a t t l e , WA) a n d a C i n t e l T y p e 1892 ( C i n e m a - T e l e v i s i o n L t d . , L o n d o n , E n g l a n d ) . 2 . 2 . 9 S I G N A L A C Q U I S I T I O N A S t a n f o r d R e s e a r c h S y s t e m s M o d e l S R 2 4 5 c o m p u t e r i n t e r f a c e a n d a M o d e l S R 2 5 0 g a t e d i n t e g r a t o r a n d b o x c a r a v e r a g e r ( S t a n f o r d R e s e a r c h S y s t e m s I n c . , P a l o A l t o , C A ) w e r e u s e d t o a c q u i r e i n t e n s i t y d a t a f r o m t h e r e f e r e n c e a n d s i g n a l s o u r c e s . T h e M o d e l S R 2 4 5 i n t e r f a c e w a s a l s o u s e d t o f i r e t h e e x c i m e r l a s e r . C o m m u n i c a t i o n s b e t w e e n t h e C o r o n a a n d M o d e l S R 2 4 5 i n t e r f a c e w e r e b y t h e s y s t e m s e r i a l p o r t . T h e M o d e l S R 2 5 0 g a t e d i n t e g r a t o r was t r i g g e r e d w i t h a n EG&G S G D - 0 4 0 D p h o t o d i o d e m o u n t e d n e a r t h e s a m p l e h o l d e r a n d r e f e r e n c e P M T . The p h o t o d i o d e was i l l u m i n a t e d i n d i r e c t l y b y t h e e x c i m e r l a s e r . A s c r e e n c o n s i s t i n g o f a p y r e x d i s c c o a t e d w i t h a s m e a r o f A p i e z o n T y p e L v a c u u m g r e a s e ( A p i e z o n 55 P r o d u c t s L t d . , L o n d o n , E n g l a n d ) w a s p l a c e d i n f r o n t o f t h e p h o t o d i o d e t o c o n v e r t t h e UV l a s e r r a d i a t i o n t o v i s i b l e . T h e p h o t o d i o d e t r i g g e r h o u s i n g a n d c i r c u i t i s s h o w n i n F i g u r e 2 . 7 . A n a l l m e t a l h o u s i n g was u s e d t o s h i e l d a g a i n s t t h e i n t e n s e E M I e x i t i n g f r o m t h e l a s e r s n o u t . 2 . 2 . 1 0 S P E C T R A L RESPONSE CORRECTION A l l r e p o r t e d s p e c t r a h a v e b e e n c o r r e c t e d f o r s y s t e m s p e c t r a l r e s p o n s e . T h e s y s t e m s p e c t r a l r e s p o n s e w a s d e t e r m i n e d w i t h a n E l e c t r o O p t i c s A s s o c i a t e s M o d e l L - 1 0 q u a r t z l a m p a n d M o d e l P - 1 0 1 p o w e r s u p p l y ( E l e c t r o O p t i c s A s s o c i a t e s , P a l o A l t o , C A ) u s i n g t h e m e t h o d o f S t a i r [ 7 4 ] . S p e c t r a l r e s p o n s e c o r r e c t i o n f a c t o r s w e r e a p p l i e d t o r a w d a t a f i l e s c r e a t e d b y t h e i n s t r u m e n t c o n t r o l a n d d a t a a c q u i -s i t i o n p r o g r a m l i s t e d i n A p p e n d i x 1 w i t h t h e B A S I C p r o g r a m l i s t e d i n A p p e n d i x 3 . C o r r e c t i o n f a c t o r s u s e d f o r t h e o t h e r UV c u t o f f f i l t e r s a r e a l s o l i s t e d i n A p p e n d i x 3 . S p e c t r a w e r e n o t c o r r e c t e d f o r h i g h e r o r d e r d i f f r a c t i o n . 2 . 2 . 1 1 C A B L I N G T h e s e r i a l p o r t c a b l e b e t w e e n t h e C o r o n a a n d t h e M o d e l S R 2 4 5 i n t e r f a c e h a d t w o e x t e r n a l m e t a l b r a i d s h i e l d s c o n n e c -t e d t o a l l m e t a l s h i e l d e d c o n n e c t o r s o c k e t s a n d p l u g s . The c a b l e b e t w e e n t h e C o r o n a p a r a l l e l p r i n t e r p o r t a n d i s o l a t i o n r e l a y a n d M o d e l 7 0 0 - 5 1 s c a n c o n t r o l l e r a l s o h a d t w o e x t e r n a l m e t a l b r a i d s h i e l d s c o n n e c t e d t o a l l m e t a l s o c k e t s a n d p l u g s . 5 0 t r i a x c a b l e ( B e l d e n 9 2 2 2 ) w i t h B N C c o n n e c t o r s w a s u s e d f o r t h e s i g n a l l i n e b e t w e e n t h e R 9 5 5 P M T a n d t h e M o d e l S R 2 5 0 g a t e d i n t e g r a t o r a s w e l l a s f o r t h e c o n n e c t i o n 56 Battery container 4' Brass tubing, black interior 40 Mesh copper screen Rpiezon "L" gease coated pyreK disc, 22 H 1.6 mm EG & 6 SCD-040D photodiode Trigger output BNC connector E G & G SGD-040D HI 9 V TRIGGER _OUT 1 M E G m Figure 2.7 Photodiode tr i g g e r housing and c i r c u i t diagram. 57 b e t w e e n t h e e x c i m e r l a s e r a n d t h e M o d e l S R 2 4 5 i n t e r f a c e . A l l o t h e r c o n t r o l a n d s i g n a l l i n e s w e r e 50 Q c o a x i a l c a b l e ( A m p h e n o l 0 3 5 5 4 ) w i t h BNC c o n n e c t o r s . A l l i n s t r u m e n t c o m p o -n e n t s w e r e c o n n e c t e d t o a common s i n g l e - p o i n t g r o u n d . 2 . 2 . 1 2 E L E C T R I C A L POWER S e r i o u s p r o b l e m s w e r e e n c o u n t e r e d w i t h e l e c t r i c a l p o w e r d i s t r i b u t i o n l i n e s i n t h e b u i l d i n g . T h e p r o b l e m f i r s t b e c a m e a p p a r e n t b y a r a p i d l y s h r i n k i n g a n d e x p a n d i n g d i s p l a y o n t h e c o m p u t e r m o n i t o r . S i g n i f i c a n t s h o r t a n d l o n g t e r m f l u c t u a t i o n s i n p o w e r l i n e v o l t a g e w e r e a d a i l y o c c u r r e n c e a n d a d v e r s e l y a f f e c t e d m e a s u r e m e n t s . A s i m p l e m o n i t o r c o n s i s t i n g o f a s t e p d o w n t r a n s f o r m e r a n d b r i d g e r e c t i f i e r c o n n e c t e d t o a l a b o r a t o r y c h a r t r e c o r d e r was u s e d t o f o l l o w l i n e v o l t a g e f l u c t u a t i o n s . T y p i c a l l i n e v o l t a g e s w i n g s e n c o u n t e r e d a r e i l l u s t r a t e d i n F i g u r e 2 . 8 . T h i s p r o b l e m w a s a l l e v i a t e d b y h a v i n g a n e w s u p p l y c i r c u i t i n s t a l l e d f o r l a s e r u s e o n l y a n d u s i n g c o n s t a n t v o l t a g e s u p p l y d e v i c e s f o r o t h e r i n s t r u m e n t c o m p o n e n t s . A S o l a M o d e l 2 0 - 2 5 - 2 2 0 E 8 2 9 c o n s t a n t v o l t a g e t r a n s f o r m e r ( S o l a E l e c t r i c C o m p a n y , C h i c a g o , I L ) w a s u s e d t o s u p p l y t h e c o m p u t e r , a n d M o d e l 7 0 0 - 5 1 s c a n c o n t r o l l e r . A n R T E D E L T E C M o d e l M P C 1 5 6 0 1 2 0 / 1 2 0 ( R T E D E L T E C , S a n D i e g o , C A ) l i n e c o n d i t i o n e r w a s u s e d t o p o w e r t h e PMT p o w e r s u p p l i e s , p e a k d e t e c t o r , M o d e l S R 2 4 5 i n t e r f a c e a n d M o d e l S R 2 5 0 g a t e d i n t e g r a t o r . 2 . 2 . 1 3 E L E C T R O M A G N E T I C I N T E R F E R E N C E E l e c t r o m a g n e t i c i n t e r f e r e n c e ( E M I ) w a s a s o u r c e o f 58 MINUTES Figure 2.8 Power l i n e voltage fluctuations. 59 considerable d i f f i c u l t y and f r u s t r a t i o n i n attempts to take r e l i a b l e measurements. Despite using many standard [75-77] techniques to a l l e v i a t e t h i s problem, EMI was the l i m i t i n g factor i n obtaining credible l i f e t i m e measurements. Some of the p r a c t i c a l consequences of EMI encountered were d i g i t a l equipment lockup, anomalous t r i g g e r i n g , corrupted data f i l e s , s ignal noise, and insidious equipment malfunctions. Some of the EMI sources encountered were microwave discharges, Tesla c o i l s , warning sign flasher, the excimer l a s e r , and s e v e r a l sources of unknown o r i g i n that were e x t e r n a l to the l a b o r a t o r y . The combination of t r a n s i e n t EMI phenomena with several independently acting EMI sources consumed an inordinate amount of time and e f f o r t i n attempts to obtain r e l i a b l e data. The EMI from a l l l a b o r a t o r y sources other than the excimer laser and Tesla c o i l was successfully controlled by a combination of robust shielding and single-point grounding [75] of a l l instrument components. The Corona computer would lock up whenever a T e s l a c o i l was used i n an a d j o i n i n g laboratory, the EMI apparently entering the computer through i t s keyboard. An e f f e c t i v e EMI shi e l d was impractical and T e s l a c o i l use was b r i e f and i n f r e q u e n t , so the instrument was not run whenever an energized Tesla c o i l was nearby. The excimer laser was an intractable, vexing source of EMI. The beam snout and power cord were the p o i n t s of EMI emission from the excimer l a s e r , a l l other l e a k i n g areas having been sealed with RF gasket or low pass f i l t e r s . 60 E f f e c t i v e emission reduction from the snout and power cord was impractical since i t would have involved major modifica-t i o n s to the excimer l a s e r without guaranteed success. Power l i n e introduction of EMI to the instrument components was eliminated by use of a power l i n e conditioner. Radiated EMI was p a r t i c u l a r l y troublesome since i t s severity at any given point i n space was a l t e r e d by the presence of nearby objects. The waveforms i n Figure 2.9 were taken with a Tektronix Model 2430A d i g i t a l s t o r a g e o s c i l l o s c o p e ( T e k t r o n i x , Beaverton, OR) and i l l u s t r a t e the magnitude of the EMI problem. The signals shown are an average of 256 waveforms captured from the 1P28 r e f e r e n c e PMT f o r two d i f f e r e n t lengths of cable between the reference PMT output terminal and o s c i l l o s c o p e input t e r m i n a l . O s c i l l o s c o p e t r i g g e r i n g was done by the s i g n a l from the 1P28 r e f e r e n c e PMT. The sharp r i s e at p o int T and the gradual decay i n region F i s due to l i g h t emitted by the the calcium tungstate screen on excitation at 193 nm from the excimer laser. The f l u c t u a -t i o n s i n regions P are spurious s i g n a l s caused by EMI from the excimer laser that are emitted immediately prior to the actual laser pulse. The fluctuations i n regions F are also due to EMI from the excimer laser. The p r i n c i p a l period of the f l u c t u a t i o n s i s about 9 ns, r e g a r d l e s s of s i g n a l cable length; t h i s i s a l s o the nominal l a s e r pulse width when using an ArF f i l l gas. E a r l i e r attempts to c h a r a c t e r i z e excimer laser EMI f a i l e d because the oscilloscopes available 6 1 SINGLE L E N G T H C A B L E 1 ' 1 1 1 ' 1 1 1 ' r -• . • 0.2 Q4 Q.6 0.8 lO xlE-6 5 E C DOUBLE C A B L E LENGTH T 1 1 1 1 ' 1 1 1 ' 1 • . • Q.2 D.4- 0.6 O.B lO x1E-6 Figure 2.9 EMI from excimer l a s e r ; r egion P - before laser pulse, region T - during pulse, region F - a f t e r l a s e r pulse: (A) 1.0 m s i g n a l cable length, (B) 2.0 m signal cable length. 62 w e r e s u b j e c t t o s p u r i o u s t r i g g e r i n g c a u s e d b y E M I e m i t t e d p r i o r t o t h e a c t u a l l a s e r p u l s e . C o n s e q u e n t l y , c r e d i b l e d a t a may o n l y b e c o l l e c t e d w h e n t h e r e i s a t l e a s t a 1 0 0 n s d e l a y f r o m t h e t i m e t h e l a s e r p u l s e a r r i v e s t o t h e s a m p l e g a t e o p e n i n g o n t h e M o d e l 2 5 0 g a t e d i n t e g r a t o r . T h u s , t h e s p e c t r o m e t e r i s e f f e c t i v e l y l i m i t e d t o s t u d i e s o n s p e c i e s h a v i n g l u m i n e s c e n c e l i f e t i m e s g r e a t e r t h a n a b o u t 100 n s . 2 .3 COMPOUND P R E P A R A T I O N The c o m p o u n d s e x a m i n e d i n t h i s s t u d y w e r e m i x e d o x i d e i n o r g a n i c i n s u l a t o r s i n p o w d e r f o r m . A l l c o m p o u n d s w e r e p r e p a r e d b y p r e c i p i t a t i o n f r o m a q u e o u s s o l u t i o n . T h e c o m -p o u n d s p r e p a r e d w e r e p u l v e r i z e d i n a n a g a t e m o r t a r a n d p e s t l e p r i o r t o s t o r a g e i n g l a s s v i a l s . D e i o n i z e d w a t e r o f i o n i c p u r i t y b e t t e r t h a n 10 M f t - c m w a s u s e d i n a l l p r o c e -d u r e s . R e a g e n t s u s e d a r e l i s t e d i n T a b l e I . C a r e w a s t a k e n i n a l l s t a g e s t o m i n i m i z e c o n t a m i n a t i o n . A l l g l a s s w a r e u s e d w a s c l e a n e d b y s o a k i n g i n 4 M HNO3 r w a s h i n g w i t h a 1% E x t r a n ® ( B D H C h e m i c a l s , T o r o n t o , O n t . ) s o l u t i o n , a f i n a l r i n s e w i t h d e i o n i z e d w a t e r f o l l o w e d b y o v e n d r y i n g . P l a t i n u m c r u c i b l e s w e r e c l e a n e d b y s o a k i n g i n 4 M HNO3 o v e r n i g h t [ 7 8 ] , f o l l o w e d b y u l t r a s o n i c a g i t a t i o n i n a 50% E x t r a n s o l u t i o n , d e i o n i z e d w a t e r f i n a l r i n s e a n d o v e n d r y i n g . O p e r a t i o n s w e r e c a r r i e d o u t i n c o v e r e d v e s s e l s w h e r e v e r p o s s i b l e . 2 .3 .1 MOLYBDATES AND TUNGSTATES A l k a l i n e e a r t h a n d h e a v y m e t a l t u n g s t a t e s w e r e p r e p a r e d 63 Table I REAGENTS Compound Grade Source Catalog No. Ba(N03>2 ACS Bi TMI 2 CaCC-3 ACS CdCl 2-2iH 20 ACS HCl, Cone. ACS MCB Spex BDH Fisher BDH BX 100 BI 03-20 ACS 174 72065 ACS 393-41 HfOCl 2*8H 20 HNO3, Cone. Methanol MgO Na2Mo04'2H20 Gold Label ACS Pesticide ACS ACS Ald r i c h BDH BDH MCB BDH 22,965-2 ACS 579-43 B90234 MX 65 ACS 822 Na2W04*2H20 Oxalic acid PbO Sb SrCl 2*6H 20 ACS ACS TMI 1 0 TMI 2 ACS BDH BDH Spex Spex BDH ACS 873 ACS 594 PB 75-10 SB 03-5 ACS 882 TINO3 Zn Zr0Cl 2«8H 20 Analar Reagent Gold Label BDH Fisher A l d r i c h B042310 Z-11 20,502-8 1) Source: Matheson, Coleman & B e l l , Norwood, OH Spex Industries, Inc., Edison, NJ BDH Chemicals Ltd., Toronto, Ont. Fisher S c i e n t i f i c Co., Pittsburgh. PA Aldr i c h Chemical Co., Inc., Milwaukee, WI 64 as follows [79,80]: Ten ml of LOOM al k a l i n e earth or heavy metal chloride solution was added to a 125 ml Erlenmeyer f l a s k containing 0.010 moles of Na2W04'2H20 dissolved i n approximately 25 ml water. The s l u r r y was warmed to approximately 90 °C f o r about two hours with periodic agitation, and then allowed to s i t overnight at room temperature [81], The supernatant l i q u i d was decanted o f f and precipitates were washed three times by adding about 25 ml water, warming f o r about one hour at about 90 °C with p e r i o d i c a g i t a t i o n , a l l o w i n g to s e t t l e out overnight at room temperature and then decanting o f f the supernatant l i q u i d . The washed p r e c i p i t a t e s were then d r i e d by f i l t e r i n g o f f e x c e s s water by vacuum f i l t r a t i o n using Whatman No. 52 f i l t e r paper, then drying at 110 °C. The d r i e d compounds were then annealed [82] i n covered platinum c r u c i b l e s at 800 °C f o r 4 h i n a muffle furnace. The corresponding molybdates [83] as well as the mixed c r y s t a l series Ca(Mo x Wy)C>4, Sr(Mo x Wy)04, (Ca x Sr y)Mo04 a n d (Ca x Sry)WC>4, where x + y = 1, were prepared i n an analogous manner. The z i n c , cadmium and lead p r e c i p i t a t e s were gelatinous and took several days to s e t t l e out. Yields were b e t t e r than 98% f o r the a l k a l i n e e a r t h compounds and exceeded 80% for the heavy metal s a l t s . 2.3.2 ZIRCONATES AND HAFNATES A l k a l i n e earth z i r c o n a t e s and hafnates were prepared v i a oxalate intermediates [84-87] i n the following manner: 65 One m l o f 1 .00 M a l k a l i n e e a r t h c h l o r i d e ( 5 . 0 0 m l o f 0 . 2 M B a N 0 3 ) w a s a d d e d t o a 1 2 5 m l E r l e n m e y e r f l a s k c o n t a i n i n g 0 . 0 0 1 0 m o l e s o f z i r c o n y l ( o r h a f n y l ) c h l o r i d e d i s s o l v e d i n a b o u t 5 m l w a t e r , T h e s o l u t i o n w as w a r m e d t o a b o u t 80 ° C a n d 2 . 5 m l o f h o t 1.0 M o x a l i c a c i d w a s a d d e d . T h e s o l u t i o n was w a r m e d t o n e a r b o i l i n g f o r 30 m i n u t e s a n d p e r i o d i c a l l y a g i t a t e d [ 8 8 ] , T h e s o l u t i o n w a s a l l o w e d t o s e t t l e o v e r n i g h t a t r o o m t e m p e r a t u r e . T h e s o l u t i o n was t h e n c o o l e d i n a n i c e b a t h a n d s u p e r n a t a n t l i q u i d d e c a n t e d o f f . T h e p r e c i p i t a t e was t h e n w a s h e d t h r e e t i m e s w i t h c o l d w a t e r [ 8 9 ] i n a n i c e b a t h a n d t r a n s f e r r e d a s a s l u r r y t o a c o v e r e d p l a t i n u m c r u c i b l e . On s e t t l i n g , t h e s u p e r n a t a n t l i q u i d was d e c a n t e d o f f , t h e p r e c i p i t a t e w as d r i e d a t 110 ° C , a n d t h e n i g n i t e d i n a m u f f l e f u r n a c e f o r 4 h a t 900 ° C . D o p e d z i r c o n a t e s a n d h a f n a t e s w e r e p r e p a r e d i n a n a n a l o g o u s m a n n e r w i t h 1 .00 m l o f 0 . 0 0 1 M d o p a n t s o l u t i o n ( B i , P b , T l i n . 0 . 1 M HNO3, sb i n 0.1 M H C I ) a d d e d p r i o r t o a d d i t i o n o f t h e a l k a l i n e e a r t h s o l u t i o n . Y i e l d s f o r a l l a l k a l i n e e a r t h z i r c o n a t e s a n d h a f n a t e s p r e p a r e d e x c e e d e d 90%. 2 .4 COMPOUND A N A L Y S I S R e p r e s e n t a t i v e s a m p l e s o f t h e c o m p o u n d s p r e p a r e d w e r e a n a l y z e d b y x - r a y p o w d e r d i f f r a c t i o n [ 9 0 ] . T h e i n s t r u m e n t u s e d was a P h i l i p s M o d e l P W 1 0 0 8 / 8 5 X - r a y p o w d e r d i f f r a c t o -m e t e r w i t h M o d e l P W 1 0 2 4 / 1 0 p o w d e r c a m e r a , M o d e l PW1033 m o t o r d r i v e r a n d M o d e l P W 1 0 1 2 / 2 0 c a m e r a m o u n t a n d f i l t e r h o l d e r ( P h i l i p s E l e c t r o n i c I n s t r u m e n t s , M a h w a h , N J ) . T h e X - r a y 66 source used was a copper t a r g e t X-ray tube run at 38 kV, 25 mA with a n i c k e l f i l t e r . Powder samples were held i n 0.3 mm c a p i l l a r y tubes; exposure was 4 h using Kodak type DEF-392 d i r e c t exposure f i l m . For each sample, the c a l c u l a t e d d values and t h e i r associated v i s u a l l y estimated peak i n t e n s i t i e s were compared ag a i n s t values l i s t e d i n the ASTM X-ray powder data f i l e . Results are tabulated i n Table II. The X-ray powder data i s i n good agreement with l i t e r a t u r e data f o r the compounds examined and also shows that contamination from simple metal oxides i s not present i n appreciable quantities. Selected samples were analyzed by neutron a c t i v a t i o n to confirm t h e i r elemental composition and check f o r the presence of impurities. The analyses were done by Novatrack at the TRIUMF f a c i l i t y on the University of B r i t i s h Columbia campus. Resu l t s are l i s t e d i n Table I I I . Approximately 100 mg samples were used f o r the molybdate and tungstate s a l t s . 67 Table II X-ray Power D i f f r a c t i o n Data for Alkaline Earth Zirconates and Hafnates CaZr0 3 SrZrO-3 BaZrC«3 d f A 100 ^•^max d, A 100 I/Imax d, A 100 I/I. 2.408 1 2.600 <1 1 .792 1 2.002 20 2.368 <1 1 .704 60 1 .816 40 2.049 30 1 .610 <1 1 .792 2 1 .983 <1 1 .526 2 1 .650 5 1 .674 50 1 .479 20 1 .621 10 1 .450 1 0 1 .322 20 1 .547 10 1 .296 1 0 1 .274 1 1 .480 <1 1 .183 2 1 .247 2 1 .441 <1 1 .209 10 1 .416 5 1 .283 1 max 1.266 1 1.199 <1 1.176 2 1.148 2 Table I I (contd.) X-ray Power D i f f r a c t i o n Data for Alkaline Earth Zirconates and Hafnates CaHf0 3 SrHf0 3 BaHf0 3 d, A 100 •'•/•^max o d, A d, A 100 I / I m a x 3 . 9 6 9 100 4 . 5 9 9 <1 2 .931 100 2 . 9 3 6 50 4 . 6 2 3 1 0 2 . 0 7 8 30 2 . 8 4 9 10 4 . 7 4 5 2 1 . 7 9 9 <1 2.81 4 100 2 . 8 8 0 100 1 . 6 9 8 80 2 . 7 8 0 10 2 . 5 6 0 1 1 .471 10 2 . 5 5 0 5 2 . 1 7 3 1 1 . 3 1 6 20 2 . 4 0 5 1 2 . 0 4 0 40 1 . 2 0 3 5 2 . 3 3 0 <1 1 . 8 2 2 1 0 2 . 2 7 9 <1 1 . 6 6 7 60 1 . 9 9 4 80 1 .541 2 1 . 8 0 7 20 1 . 4 4 4 20 1 . 7 8 4 20 1 .361 5 1 . 642 30 1 . 2 9 2 30 1 . 6 1 6 30 1 .1 79 5 1 . 5 4 0 10 3 . 5 0 7 2 1 . 4 7 7 <1 1 . 4 1 3 5 1 . 3 3 8 <1 1 . 262 10 TABLE III Expected and Measured Composition of Molybdate and Tungstate Salts Prepared Compound Ca, % Sr, % Mo, % W, % Sr(Mo 02 W 98)04 26.26* 0.575 53.99 (24.5) (<0.5) (50.5) Sr(Mo 0 5 W 9 5 ) 0 4 26.45 1.449 52.76 * * (27.8) (2.3) (50.2) Sr(Mo 1 0 W 9 0 ) 0 4 26.82 2.937 50.65 (19.5) (3.8) (45.2) Sr(Mo 1 5 W 8 5 ) 0 4 27.19 4.465 48.49 * 1 5 * (21.7) (5.8) (45.6) Sr(Mo 20 W 80)04 27.56 6.036 46.27 * ° U (24.7) (7.0) (41.5) Sr(Mo 05 W 7 5 ) 0 4 27.95 7.651 43.99 * * (24.7) (7.4) (43.0) Sr(Mo ™ W 7 0 ) 0 4 28.35 9.312 41.64 * * (28.9) (9.5) (40.0) Ca(Mo 01 W 9 9 ) 0 4 13.96 0.334 63.41 (14.9) (<-05) (60.1) Ca(Mo 0 2 W 9 s ) 0 4 14.01 0.671 62.96 ' * (15.2) (<0.9) (60.6) Ca(Mo.Q5 W.95)04 Ca(Mo.20 W.80)°4 Ca(Mo. 3 0 W. 7 0)O 4 14.14 1.692 61.60 (10.7) (2.9) (52.3) Ca(Mo 10 w 90)°4 14.36 3.437 59.23 (14.8) (3.8) (55.2) Ca(Mo 15 W 8 5 ) 0 4 14.59 5.238 56.88 •'^ - 0 3 (16.0) (6.0) (53.9) 14.83 7.098 54.40 (16.8) (8.7) (53.5) Ca(Mo 05 W 7 5 ) 0 4 15.07 9.019 51.85 ' 3 (15.9) (9.5) (51.8) 15.23 11.004 49.20 (15.6) (12.8) (48.7) * Values measured by neutron a c t i v a t i o n i n parentheses, a l l values are expressed i n percent by weight. 70 Chapter 3 DATA REDUCTION 3.1 OVERVIEW In t h i s chapter the data r e d u c t i o n technique used f o r e x t r a c t i n g u s e f u l i n f o r m a t i o n from a t i m e - w a v e l e n g t h r e s o l v e d luminescence spectrum i s d e s c r i b e d and the algo-rithm's performance i s evaluated. 3.2 SYSTEM MODEL In an i n o r g a n i c s o l i d , the c o n f i g u r a t i o n coordinate model d i s c u s s e d i n s e c t i o n 1.6.5 g e n e r a l l y gives a good description of the emission and absorption spectra associ-ated with a l o c a l i z e d excitation. To a f i r s t approximation, the emission band shape i s Gaussian and can be described by a function which i n d u e s the parameters of peak maxima, peak width, and an i n t e n s i t y factor: S v = K a exp((m-v) 2/(cw 2)) (3.1) where v i s frequency (cm - 1)» K a i s a constant p r o p o r t i o n a l to the q u a n t i t y of e m i t t e r , m i s the peak maxima (cm~1), w i s the peak h a l f w i d t h ( c m - 1 ) , S v i s the observed lumines-cence i n t e n s i t y at frequency v, and c i s a constant r e l a t -ing halfwidth to standard deviation. In many simple systems the skewness and kurtosis terms [40,91] are i n s i g n i f i c a n t . In simple systems where energy migration processes are n e g l i g i b l e , luminescence decay proceeds by f i r s t - o r d e r k i n e t i c s as d i s c u s s e d i n s e c t i o n 1.3.1. The instantaneous luminescence i n t e n s i t y observed at a time t following pulsed 71 e x c i t a t i o n i s given by the rel a t i o n s h i p : T t = K b exp(-t/t) (3.2) where i s the observed luminescence i n t e n s i t y at time, t, a f t e r the e x c i t a t i o n pulse, K b i s a constant proportional to the quantity of emitter, T i s the i n t r i n s i c l i f e t i m e of the emitting species. When luminescence i n t e n s i t y i s measured with a gated integrator having a time window width of At: t+At T t = K b / exp(-t/T) dt (3 .3) a f t e r i n t e g r a t i n g (3.3) and c o l l e c t i n g terms, the measured int e n s i t y i s given by the relationship: T t = K b T [ exp(-t/x) - exp(-(t+At)/x) ] ( 3 .4 ) By combining (3 .1 ) and ( 3 . 4 ) , the time-wavelength r e s o l v e d luminescence spectrum may be expressed i n matrix form as: [D] = [S] [T] (3 .5) where [D] i s a i x j data matrix of luminescence i n t e n s i t i e s f o r i wavelengths and j times, [S] i s a i x 1 c o n c e n t r a t i o n term and spectrum vector, [T] i s a 1 x j normalized time behavior vector. The i t h and j t h values for the [S] and [T] vectors are given by the relat i o n s h i p s : S ± = c exp((m-v i) 2/(cw 2)) (3.6) 72 T j = T [ e x p ( - t j / x ) - e x p ( - ( t j + A t ) / T ) ] ( 3 . 7 ) w h e r e i s t h e s p e c t r a l r e s p o n s e v a l u e a t f r e q u e n c y v-^, C i s a c o n s t a n t t e r m p r o p o r t i o n a l t o t h e q u a n t i t y o f e m i t t e r , a n d T j i s t h e n o r m a l i z e d i n t e n s i t y v a l u e a t g a t e o p e n i n g t i m e t j f o r a g a t e w i d t h A t . I n t h e s i t u a t i o n w h e r e s e v e r a l e m i t t i n g s p e c i e s a r e p r e s e n t , t h e o b s e r v e d l u m i n e s c e n c e i s a f u n c t i o n o f a l l s p e c i e s p r e s e n t a n d a n y i n t e r a c t i o n s t h a t m a y t a k e p l a c e b e t w e e n t h e m a n d c o n c o m i t a n t s i n t h e l a t t i c e . I f e a c h s p e c i e s a c t s i n d e p e n d e n t l y a n d t h e o b s e r v e d l u m i n e s c e n c e i s a l i n e a r c o m b i n a t i o n o f t h e e m i s s i o n f r o m e a c h s p e c i e s p r e s e n t , t h e n f o r t h e c a s e w h e r e n s p e c i e s a r e p r e s e n t , t h e i x 1 [ S ] ( 3 . 6 ) a n d t h e 1 x j [ T ] ( 3 . 7 ) v e c t o r s m a y b e r e p l a c e d b y i x n a n d n x j m a t r i c e s r e s p e c t i v e l y i n ( 3 . 5 ) . T h e s y s t e m m o d e l ( 3 . 5 ) d e s c r i b e s t h e t i m e - w a v e l e n g t h r e s o l v e d s p e c t r u m f r o m a n y g i v e n c o m p o n e n t i n t e r m s o f f o u r p a r a m e t e r s : p e a k m a x i m a , p e a k w i d t h , i n t e n s i t y f a c t o r , a n d l i f e t i m e . T h u s , i n p r i n c i p l e , t h e s p e c t r u m f r o m a m a t e r i a l c o n t a i n i n g n e m i t t i n g c o m p o n e n t s m a y b e d e s c r i b e d w i t h 4 n p a r a m e t e r s . 3.3 O P T I M I Z A T I O N AND P A R A M E T E R E S T I M A T I O N T h e s y s t e m m o d e l i s a n o n l i n e a r f u n c t i o n o f t h e p a r a -m e t e r s o n b o t h t h e t i m e a n d w a v e l e n g t h d o m a i n s , i t c a n n o t b e l i n e a r i z e d f o r a s y s t e m c o n t a i n i n g t w o o r m o r e c o m p o n e n t s . S o l v i n g t h e m a t r i x e q u a t i o n ( 3 . 5 ) a n d c o m p u t i n g t h e p a r a -m e t e r v a l u e s f r o m e x p e r i m e n t a l d a t a was a t t e m p t e d b y u s i n g 73 optimization techniques to a r r i v e at a minimum error value between experimental data and a spectrum computed from estimated parameter values. Two optimization methods were attempted to f i n d parameter values: simplex optimization and the extended Kalman f i l t e r . 3.3.1 SIMPLEX OPTIMIZATION A simplex [92] i s a geometric figure that has one more vertex than the dimensions of the space i n which i t i s defined; i t includes a l l interconnecting l i n e segments and polygonal faces. For example, i t i s a t r i a n g l e i n two dimensions and i s a tetrahedral figure i n three dimensional space. In simplex optimization, each vertex of the simplex i s assigned to an a t t r i b u t e of the system under study that i s to be minimized. The optimization procedure i s a c o l l e -c t i o n of r u l e s f o r tumbling the simplex through parameter space i n order to achieve the minimization of the attribute i n question. The simplex algorithm o r i g i n a l l y formulated by Spendley et a l . [93] has been modified by numerous investigators [94-98] to a c c e l e r a t e convergence or avoid t r a p p i n g i n l o c a l minima. The simplex a l g o r i t h m used i n t h i s study i s the m o d i f i c a t i o n of Nelder and Mead [99]. The implementation f o l l o w s that d e s c r i b e d by Daniels [100], This v e r s i o n i s one of the s i m p l e s t implementations, yet i t i s robust [92,100,101] with slow convergence being i t s only s e r i o u s drawback. The procedure f o r a two parameter system i s as follows: 74 (1) Create a three point simplex by guessing three d i f f e r e n t values f o r each parameter, evaluate the f u n c t i o n (or c a r r y out the process) and p l o t the responses as i n F i g u r e 3.1. The three response values are: low point (LP), high point (HP) and next highest point (NHP). (2) C a l c u l a t e the c e n t r o i d , CN, ( i n a two parameter system i t l i e s midway between the LP and NHP); then c a r r y out a r e f l e c t i o n operation by extending a l i n e from HP through CN. The d i s t a n c e between HP and CN i s x, the r e f l e c t e d p o i n t , R , l i e s along the l i n e at a d i s t a n c e ax from CN as i l l u s t r a t e d i n F i g u r e 3.1. The constant, a, i s c a l l e d the r e f l e c t i o n c o e f f i c i e n t and i s s l i g h t l y less than 1 to avoid o s c i l l a t i o n problems. A new response value f o r the system at point R i s obtained by evalu-ating the function (or carrying out the process) for the parameters at that point. (3) I f the r e f l e c t i o n o p e r a t i o n i s moderately s u c c e s s f u l , where the response values are: L P S R < H P , then a new simplex i s formed by r e p l a c i n g HP with R , and c a r r y i n g out the r e f l e c t i o n operation again i n step (2). (4) I f the r e f l e c t i o n o p e r a t i o n i s very s u c c e s s f u l , where the response values are: R<LP, an expansion operation i s c a r r i e d out by forming a new point, E, at a d i s t a n c e cx from CN along the r e f l e c t i o n l i n e as i l l u s t r a t e d i n F i g u r e 3.1. The expansion c o e f f i c i e n t , c, i s s l i g h t l y less than 2 to avoid o s c i l l a t i o n problems. A new respo-nse value i s obtained at E. If the expansion i s succes-75 Figure 3.1 Two dimensional simplex i l l u s t r a t i n g r e f l e c t i o n , expansion, and contraction operations. 76 s f u l , that i s , E<R, then E r e p l a c e s HP. Otherwise, R replaces HP and the r e f l e c t i o n operation i s carried out again i n step (2). (5) I f the i n i t i a l r e f l e c t i o n o p e r a t i o n f a i l s , where RSHP, then a contraction operation i s carried out by forming a new point, C, at a d i s t a n c e bx from CN along the r e f l e -c t i o n l i n e as i l l u s t r a t e d i n Figu r e 3.1. The contra-ction c o e f f i c i e n t , b, i s s l i g h t l y less than 0.5 to avoid o s c i l l a t i o n problems. If the contraction i s successful, that i s , C<HP, the point HP i s repl a c e d by C and the r e f l e c t i o n operation i s carried out again i n step (2). (6) In r a r e cases the c o n t r a c t i o n o p e r a t i o n may f a i l . I f t h i s occurs, then the e n t i r e simplex, except f o r point LP, i s s c a l e d [100] and the o p t i m i z a t i o n procedure i s started again. (7) The r e f l e c t i o n operations are c a r r i e d out unless some termination c r i t e r i o n i s met. The termination c r i t e r i o n may be set to be something l i k e when a sequence of r e f l e c t i o n s f a i l s to reduce the response value below a set p o i n t or produces a r e d u c t i o n l e s s than some pre-determined value. 3.3.2 THE KALMAN FILTER D i g i t a l f i l t e r s [102-104] have proven u s e f u l i n para-meter e s t i m a t i o n and o p t i m i z a t i o n problems, the d i g i t a l f i l t e r s e r v i n g to separate one component of a s i g n a l from another. The Kalman f i l t e r i s a series of equations that i s the o p t i m a l s o l u t i o n [102] to the general l i n e a r f i l t e r 77 problem. I f the system to be examined i s a l i n e a r system and has only Gaussian noise, the minimum variance estimates for the system parameters given by the Kalman f i l t e r w i l l be the best possible estimates obtainable. No other l i n e a r or nonlinear estimator [105] can produce parameter estimates having lower variance. The extended Kalman f i l t e r has been a p p l i e d to non-l i n e a r systems [102,105,106] successfully to derive system parameters and deconvolute overlapped spectral peaks [105], The Kalman f i l t e r has been a p p l i e d to two dimensional systems to process images [107] and to two and three dimen-sional systems [108] to f i t enzyme k i n e t i c data i n multicom-ponent systems. In p r i n c i p l e , the extended Kalman f i l t e r [105,108] should be r e a d i l y applied to finding parameters describing time-wavelength resolved luminescence spectra. Considerable e f f o r t was expended i n implementing the extended Kalman f i l t e r to resolve highly overlapped spectral envelopes and o b t a i n t h e i r parameters. The lack of noise data f o r the measured luminescence spectra was a suspected trouble spot. However, when t h i s data was col l e c t e d and applied the system s t i l l f a i l e d to converge. The extended Kalman f i l t e r program was very sens i t i v e to the i n i t i a l guess values for the parameters. This s e n s i t i v i t y may be due to the -system being n o n l i n e a r i n both the time and wavelength domains. Another p o s s i b i l i t y i s that the computer program written to implement the f i l t e r may have contained e r r o r s . A s a t i s -78 factory solution to the s e n s i t i v i t y problem was not obtained and work on the Kalman f i l t e r approach was abandoned. 3.4 THE DATA REDUCTION ALGORITHM Data reduction of multicomponent fluorescence spectra [109] and chromatographic peaks [110] was done for a single parameter for multiple components present by using a linear algebra construct and simplex optimization. This approach was i n c o r p o r a t e d i n the f i r s t stage of a two stage data reduction scheme to extract the concentration factor, peak maxima, peak width, and l i f e t i m e for each emitting species present i n a time-wavelength resolved luminescence spectrum. Stage I: Estimate the l i f e t i m e behavior for each emitter by the method of Knorr and Harris [109]. (a) Guess the number of e m i t t i n g species present, n, and a l i f e t i m e value, x n for each species. (b) Use equation 3.7 to construct an estimated n x j normal-ized time behavior matrix [TE]. (c) Use equation 3.8 to compute an estimated spectral beha-v i o r matrix [ SE ] by m u l t i p l y i n g the data matrix by the pseudoinverse of the estimated time behavior matrix; then an estimated data matrix [DE] using equation 3.9, and f i n a l l y use equation 3.10 to compute the squared error, SQE, between [D] and [DE]. [SE] = [D] [ T E ] T ([TE] [ T E ] T ) _ (3.8) [DE] = [SE] [TE] (3.9) 1 3 SQE = I I ( D a b - D E a b ) 2 a=1 b=1 (3.10) 79 (d) Guess new values f o r l i f e t i m e s , then repeat steps (b) and (c) using simplex optimization to minimize SQE. Stage I I : (e) Compute estimated from [SE] for the parameters C, m, and w for each of the n components present. (f) Using equation 3.6 and estimates of C, m, and w for each component, c o n s t r u c t a new i x n estimated s p e c t r a l behavior matrix [SE]. (g) Using equation 3.7 and estimated values for T , construct a new n x j estimated time behavior matrix [ TE ] . (h) Compute an estimated data matrix [DE] using equation 3.9, and the squared e r r o r , SQE from 3.10. (i) Guess new values for C, m, w, and T ; repeat steps (f) to (g) using simplex optimization minimize SQE. In step (i) one may set fixed values for any parameters for any components. This approach may be useful when attempting to characterize an unknown i n the presence of known emitters or to examine small changes i n selected parameters. 3.5 COMPUTERS AND FORTRAN COMPILERS USED The data r e d u c t i o n program was run on the f o l l o w i n g systems: (a) Perkin-Elmer 7500 series professional computer system (Perkin-Elmer Corp., Norwalk, CT), (b) Compupro IEEE 696/S-100 system with CPU 68K processor board (Compupro, Hayward, CA), (c) Corona Model PC400-HD2 computer with 8087 coprocessor. A S i l i c o n Valley Systems FORTRAN 77 compiler ( S i l i c o n V a l l e y Systems, Inc., Cupertino, CA) compiler was 80 used on the Perkin-Elmer and Compupro systems. A WATFOR-77 (WATCOM Systems Inc., Waterloo, Ont.) compiler was used on the Corona system. Processing times on the Perkin-Elmer and Compupro systems were s i m i l a r and about twice as fast as the Corona. Aside from some t e c h n i c a l problems with the Perkin-Elmer system, a l l three systems required the same number of i t e r a -tions to a r r i v e at s i m i l a r estimated parameter values. 3.6 ALGORITHM EVALUATION The program l i s t e d i n Appendix 4 was used i n evaluating the algorithm's performance on sets of s y n t h e t i c spectra. The synthetic spectra were computed using parameters s i m i l a r to those of common luminescent s a l t s such as calcium tungstate and calcium molybdate. A l l synthetic spectra were corrupted with Gaussian noise [92] at level s commonly found in experimental data taken with the time-wavelength resolved luminescence spectrometer. In order to simulate r e a l data as c l o s e l y as possible, the synthetic spectra were stored i n data f i l e s having exactly the same format as f i l e s produced by the program l i s t e d i n Appendix 1. The synthetic spectra time coverage was from 1 us to 20 us i n 1 us steps and a window width of 1 us; wavelength coverage was from 300 nm to 700 nm i n steps of 10 nm. 3.6.1 PERFORMANCE ON TWO COMPONENT MIXTURES The a l g o r i t h m was t e s t e d f o r the e f f e c t s of noise, i n i t i a l guess values, and r e l a t i v e concentrations of the two components on t h e i r parameter estimates at various degrees 81 o f o v e r l a p i n b o t h t h e t i m e a n d w a v e l e n g t h d o m a i n s . I n t h i s s e r i e s o f e x p e r i m e n t s , t h e p a r a m e t e r s a s s i g n e d t o c o m p o n e n t A w e r e h e l d c o n s t a n t w h i l e t h o s e a s s i g n e d t o c o m p o n e n t B w e r e v a r i e d a s s h o w n i n T a b l e I V . T h e p r i n c i p a l q u e s t i o n r e g a r d i n g a t w o c o m p o n e n t m i x t u r e i s how c l o s e c a n t h e l u m i n e s c e n c e e m i s s i o n e n v e l o p e s b e b e f o r e t h e a l g o r i t h m f a i l s t o p r o d u c e p a r a m e t e r e s t i m a t e s t h a t a r e w i t h i n a c c e p t a b l e e r r o r l i m i t s . T h e a l g o r i t h m ' s p e r f o r m a n c e f o r t h e c a s e w h e r e b o t h c o m p o n e n t s h a v e s i m i l a r i n i t i a l i n t e n s i t i e s i s i l l u s t r a t e d i n F i g u r e 3 . 2 . T h e p e a k s e p a r a t i o n i n t h e s p e c t r a l d o m a i n i s p l o t t e d o n t h e a b s c i s s a i n u n i t s o f p e a k h a l f w i d t h s , a n d t h e r a t i o o f l i f e t i m e s o f c o m p o n e n t B t o c o m p o n e n t A i s p l o t t e d o n t h e o r d i n a t e . T h e s h a d e d a r e a s r e p r e s e n t r e g i o n s w h e r e t h e r e l a t i v e e r r o r b e t w e e n a c t u a l a n d e s t i m a t e d p a r a m e t e r v a l u e s l i e w i t h i n t h e b o u n d s s t a t e d . T h i s f i g u r e i s t h e r e s u l t o f a p p l y i n g t h e d a t a r e d u c t i o n a l g o r i t h m t o 161 s y n t h e t i c s p e c t r a a n d p l o t t i n g t h e m a x i m u m e r r o r f o u n d f o r t h e p a r a m e t e r s f o r b o t h c o m p o n e n t s A a n d B . A f e a t u r e common t o m o s t s i t u a t i o n s e x a m i n e d i s t h a t a s t h e p e a k s e p a r a t i o n i n c r e a s e s i n t h e w a v e l e n g t h d o m a i n , t h e e r r o r i n t h e p a r a m e t e r e s t i m a t e s d e c r e a s e s t o a m i n i m u m v a l u e a n d t h e n i n c r e a s e s a g a i n a s t h e p e a k s e p a r a t i o n b e -c o m e s g r e a t e r . T h e i n c r e a s i n g e r r o r i n p a r a m e t e r e s t i m a t e s a s p e a k s e p a r a t i o n b e c o m e s g r e a t e r i s d u e t o t h e d e c r e a s i n g a m o u n t o f t h e c o m p o n e n t B s p e c t r a l e n v e l o p e i n c l u d e d i n t h e d a t a c o l l e c t i o n w i n d o w . F o r e x a m p l e , l e s s t h a n o n e h a l f o f 82 Table IV Parameter Assignments for Two Componment Mixtures Component Lifetime, us ,-1 Peak maxima, cm" Peak halfwidth, cm - 1 Intensity A 10 23000 6000 10 B vary, 0.25 to 250 vary, 14000 to 23000 6000 vary, 1 to 50 83 MAXIMUM OVERALL ERROR 0 0.5 1.0 1.5 PEAK SEPARATION Figure 3.2 Maximum e r r o r i n estimated parameters f o r both components A and B as a function of peak separa-t i o n i n both time and wavelength domains. Syn- 0 t h e t l c data with: 1% RSD noise, component B in t e - ° n s i t y = 10, other parameters as i n Table I. Guess values used: A = 12.3 us, B = 123 us. 84 t h e c o m p o n e n t B s p e c t r a l e n v e l o p e i s p r e s e n t i n t h e d a t a c o l l e c t i o n w i n d o w a t a peak, s e p a r a t i o n o f 1.5 h a l f w i d t h s . S i m i l a r b e h a v i o r i s s e e n i n t h e t i m e d o m a i n , p a r t i c u -l a r l y s o a t s h o r t l i f e t i m e s f o r c o m p o n e n t B . T h i s i s d u e t o t h e v e r y s m a l l c o n t r i b u t i o n c o m p o n e n t B m a k e s t o t h e o v e r a l l o b s e r v e d s i g n a l . S o l i t t l e o f c o m p o n e n t B i s p r e s e n t t h a t i t t e n d s t o g e t l o s t i n t h e n o i s e , a s w e l l a s b e i n g h i g h l y s e n s i t i v e t o t r u n c a t i o n e r r o r s i n t r o d u c e d w i t h t h e d a t a s t o r a g e f o r m a t u s e d . When c o m p o n e n t B h a s a r e l a t i v e l y l o n g l i f e t i m e , t h e r e i s l i t t l e c h a n g e i n i t s i n t e n s i t y w i t h i n t h e d a t a c o l l e c t i o n w i n d o w . T h i s r e s u l t s i n a n i n c r e a s i n g u n c e r t a i n t y i n i t s l i f e t i m e e s t i m a t e . T h e s e e f f e c t s a r e i l l u s t r a t e d i n F i g u r e 3 . 3 . I n F i g u r e 3 . 3 a , a l l p a r a m e t e r s f o r b o t h c o m p o n e n t s w e r e e s t i m a t e d w i t h a m a x i m u m e r r o r o f l e s s t h a n 2%. I n F i g u r e 3 . 3 b , a l l p a r a -m e t e r s f o r c o m p o n e n t A w e r e e s t i m a t e d w i t h i n 1 % o f t h e a c t u a l v a l u e s w h e r e a s t h e p a r a m e t e r e s t i m a t e s f o r c o m p o n e n t B w e r e a l l g r e a t e r t h a n 10%. T h i s p o o r p e r f o r m a n c e i s d u e t o t h e s m a l l s i g n a l e n v e l o p e f r o m c o m p o n e n t B ; i t s p e a k m a x i m a l i e s o u t s i d e t h e d a t a c o l l e c t i o n w i n d o w a n d i t s s h o r t l i f e t i m e y i e l d s s c a n t i n f o r m a t i o n o n t i m e b e h a v i o r . T h e a l g o r i t h m ' s p e r f o r m a n c e f o r e s t i m a t i n g i n d i v i d u a l p a r a m e t e r s f o r e a c h c o m p o n e n t a r e i l l u s t r a t e d i n F i g u r e s 3 . 4 , 3 . 5 , a n d 3 . 6 . O f t h e f o u r p a r a m e t e r s , p e a k m a x i m a a n d p e a k w i d t h c o n s i s t e n t l y s h o w e d t h e l e a s t e r r o r r e g a r d l e s s o f p e a k s e p a r a t i o n , a d d e d n o i s e , l i f e t i m e s , o r r e l a t i v e i n t e n -s i t i e s . T h e e r r o r s f o r c o m p o n e n t A p a r a m e t e r e s t i m a t e s a r e 85 Figure 3.3 Synthetic spectra with 1% RSD noise added, v e r t i -c a l a x i s : i n t e n s i t y . (a) L i f e t i m e s : A = 10 us, B = 25us; peak maxima: A = 435 nm, B = 465 nm. (b) L i f e t i m e s : A = 10 us, B = 1 us; peak maxima: A = 435 nm, B = 71 4 nm. 86 0 . 5 1 . 0 P E A K S E P A R A T I O N 1 . 5 0 . 5 1 . 0 P E A K S E P A R A T I O N Figure 3.4 Maximum e r r o r i n estimated parameters f o r both components A and B. (a) L i f e t i m e s , (b) peak i n t e n s i t i e s , (c) peak maxima, (d) peak halfwidth. S y n t h e t i c data with: 1% RSD noise, component B i n t e n s i t y =10, other parameters as i n Table I. Guess values used: A = 12.3 us, B = 123 ys. 87 a b 0.5 1.0 P E A K S E P A R A T I O N 1 . 5 HI-' z z UJ LU Z Z oo 0.0. oo o o < CC 10.0 1 . 0 0 . 1 0 . 5 1 . 0 P E A K S E P A R A T I O N 1 . 5 Figure 3.5 Maximum error i n estimated parameters for compo-nent A only, (a) L i f e t i m e s , (b) peak i n t e n s i t y , (c) peak maxima, (d) peak halfwidths. Synthetic data with: 1% RSD noise, component B in t e n s i t y = 10, other parameters as i n Table I. Guess values used: A = 12.3 ys, B = 123 ys. 88 0 . 5 1.0 1 . 5 U W ! > P E A K S E P A R A T I O N P E A K S E P A R A T I O N igure 3.6 Maximum error i n estimated parameters f o r compo-nent B only, (a) L i f e t i m e s , (b) peak i n t e n s i t y , (c) peak maxima, (d) peak halfwidths. Synthetic data with: 1 % RSD noise, component B i n t e n s i t y = 10, other parameters as i n Table I. Guess values used: A = 12.3 y s , B = 123 ys. 89 shown i n Figure 3.5, they are generally acceptable with the in t e n s i t y factor being most prone to error. The results for component B parameter estimates are given i n Fig u r e 3.6. This f i g u r e i l l u s t r a t e s w e l l the d i f f i c u l t i e s encountered with low signal l e v e l s from component B due to short l i f e -times and l a r g e p o r t i o n s of the s p e c t r a l envelope l y i n g outside the data c o l l e c t i o n window. The e f f e c t of noise on the algorithm's performance i s demonstrated i n Figure 3.7. The error shown i s the maximum found for any parameter for any component. To the synthetic s p e c t r a , Gaussian noise was added at l e v e l s ranging from zero to f i v e percent r e l a t i v e standard d e v i a t i o n . In t h i s p a r t i c u l a r experiment the l i f e t i m e values from stage I of the data reduction algorithm were held constant during stage II of the data r e d u c t i o n process. The p r e v i o u s l y noted trends i n estimated parameter r e l i a b i l i t y were reinforced i n thi s series of experiments as can be seen i n Figure 3.7. To a f i r s t approximation, the error l e v e l found the parameter estimates i s p r o p o r t i o n a l to the noise l e v e l i n the data examined. A s i g n a l noise l e v e l of 1% RSD was normally achieved with the spectrometer used i n t h i s study and th i s n o i s e l e v e l was a p p l i e d t o the s y n t h e t i c s p e c t r a i n subsequent experiments. The algorithm's s e n s i t i v i t y to i n i t i a l guess values for l i f e t i m e s i s shown i n F i g u r e 3.8. The a l g o r i t h m seems to perform b e t t e r when l i f e t i m e guesses are higher than the 90 0 . 5 1 . 0 1.5 U 1 0 P E A K S E P A R A T I O N P E A K S E P A R A T I O N P E A K S E P A R A T I O N P E A K S E P A R A T I O N Figure 3.7 Maximum e r r o r i n estimated parameters f o r both components A and B as a f u n c t i o n of added noise, (a) no noise added, (b) 1% RSD, (c) 2% RSD, (d) 3% RSD, (e) 4% RSD, (f) 5% RSD. S y n t h e t i c data with: component B i n t e n s i t y =10, other para-meters as i n Table I. Guess values used: A = 12.3 y s , B = 123 ys. 91 a 0 0 .5 1.0 1.5 P E A K S E P A R A T I O N b P E A K S E P A R A T I O N P E A K S E P A R A T I O N d P E A K S E P A R A T I O N Figure 3.8 Maximum e r r o r i n estimated parameters f o r both components A and B as a f u n c t i o n of l i f e t i m e guess values. Guess values (us) used: (a) 12.3, 123; (b) 12.3, 1.23; (c) 12.3, 7.89; (d) 123, 1.23. Synthetic data with: 1% RSD noise, compo-nent B i n t e n s i t y =10, other parameters as i n Table I. 9 2 actual l i f e t i m e s . Generally, the algorithm appears to have r e l a t i v e l y low s e n s i t i v i t y to guess values provided that they are within a factor of 10 of the r e a l l i f e t i m e values. In F i g u r e 3.9, the e f f e c t of v a r y i n g the amount of component B i n the system i s presented. The o v e r a l l trend here i s that the e r r o r i n estimated parameter values i s related to the size of the spectral envelope captured within the data c o l l e c t i o n window. This trend r e i n f o r c e s the notion that the e r r o r s i n parameter estimates are more dependent on the volume contained w i t h i n the observed spectral envelope than on the overlap of components A and B i n either the time or wavelength domains. 3.6.2 PERFORMANCE ON THREE COMPONENT MIXTURES Synthetic spectra consisting of three components were successfully resolved into the i n d i v i d u a l components. The algorithm's performance for systems containing three highly overlapped components i s shown i n the examples l i s t e d i n Table V. Generally, i f the l i f e t i m e r a t i o between any two components i s g r e a t e r than 2:1, and i f the peak s e p a r a t i o n i s b r e a t e r than 0.5 h a l f w i d t h s then the data r e d u c t i o n operation would normally be successful as demonstrated when comparing r e s u l t s for the #1 and #3 mixtures i n Table V. The algorithm was used to f i n d the number of components present i n an unknown mixture. The algorithm was run using an i n c r e a s i n g number of guessed components i n the i n i t i a l guess. The values f o r SQE at t e r m i n a t i o n were p l o t t e d a g a i n s t the number of c o n s t i t u e n t s guessed as shown i n 93 P E A K S E P A R A T I O N P E A K S E P A R A T I O N P E A K S E P A R A T I O N P E A K S E P A R A T I O N P E A K S E P A R A T I O N P E A K S E P A R A T I O N Figure 3.9 Maximum e r r o r i n estimated parameters f o r both components A and B as a f u n c t i o n of peak i n t e n -s i t y . Peak i n t e n s i t i e s used: (a) A = 10, B = 50; (b) A = 10, B = 20; (c) A = 10, B = 10; (d) A = 10, B = 5; (e) A = 1 0, B = 2; ( f ) A = 1 0 , B = 1. S y n t h e t i c data with 1% RSD noise, other para-meters as i n Table I. Guess values used: A = 12.3 us, B = 123 us. 94 Table V Comparison of A c t u a l and Estimated Parameters f o r Three Component Mixtures 9 Component Lifetime ys Maxima cm~1 Halfwidth Intensity cm-'' B 10.00 (10.05) 25.00 (25.23) 2.50 ( 2.48) 23000 (22964) 1 9400 (19382) 18200 (18204) 6000 (6023) 6000 (5999) 6000 (6008) 10.00 (10.10) 10.00 ( 9.87) 10.00 (10.07) B 1 0.00 (10.02) 25.00 (25.09) 2.50 ( 2.50) 23000 (22989) 1 9400 (19403) 15800 (15838) 6000 (6019) 6000 (6017) 6000 (6013) 1 0.00 ( 9.97) 1 0.00 ( 9.95) 1 0.00 (10.01 ) B 1 0.00 (10.22) 25.00 ( 1.85) 40.00 (33.62) 23000 (22734) 1 9400 (20398) 1 8200 (18673) 6000 (6208) 6000 (1E-8) 6000 (6101 ) 1 0.00 (10.90) 1 0.00 ( 0.72) 1 0.00 ( 9.95) a E s t i m a t e d values are i n parentheses. 1% RSD noise added; guess times, us: 36.9, 12.3, 7.89. 95 Figure 3.10. In most situations, the value of SQE decreases r a p i d l y u n t i l the c o r r e c t number of components present i s reached and then the curve decreases at a much slower r a t e or i n c r e a s e s . The r i s e i n SQE when passing the c o r r e c t number of components present i s l i k e l y due to numerical i n s t a b i l i t i e s associated with the c a l c u l a t i o n of the pseudo-inverse. This approach was a p p l i e d s u c c e s s f u l l y to f i n d the number of components present i n a r e a l material. A powder sample of Sr(Mo 0.05 w0.95)°4 w a s e x c i t e d at 193 nm and 248 nm, the measured s p e c t r a are shown i n F i g u r e 3.11. Three components are present: WO^-, M 0 O 4 " , and a long l i v e d component from the quartz c e l l used to hold the sample powder. In F i g u r e 3.12 the d i f f e r e n c e between the measured spectrum i n F i g u r e 3.11a and a spectrum created by the computed parameters are shown. The cause f o r the r i s e i n SQE when guessing four components i s l i k e l y due to numerical i n s t a b i l i t i e s i n the p s e u d o i n v e r s e c a l c u l a t i o n , a consequence of t h i s i s shown i n F i g u r e 3.12. A d d i t i o n a l refinements to the simplex a l g o r i t h m may reduce these abnormalities i n r e a l systems. 96 THREE COMPONENT SYSTEM Number of components guessed 1 Figure 3.10 P l o t of r e s i d u a l e r r o r vs number of components guessed. L i f e t i m e s , ys: A = 10, B = 25, C = 2.5; peak separations range: A - B: 0.2 to 0.6 h a l f -widths, A - C: 0.8 to 1.2 - h a l f w i d t h s ; 1% RSD noise; equal peak i n t e n s i t i e s . 97 Figure 3.11 Measured spectra for Sr(Mc• Q5 ".95)04: (a) 193 nm excitation; (b) 248 nm excitation. 98 Figure 3.12 D i f f e r e n c e s p e c t r a as a f u n c t i o n of the number of components guessed for Sr(Mo.o5 W 95)04 exci-ted at 248 nm. (a) one; (b) two; (c) three; (d) four components. 99 Chapter 4 INORGANIC POWDERS 4.1 OVERVIEW In t h i s chapter the r e s u l t s of s t u d i e s on the time-wavelength luminescence spectra of two groups of inorganic powders are presented. 4.2 TUNGSTATES AND MOLYBDATES S c h e e l i t e (calcium tungstate) i s a t e c h n o l o g i c a l l y important compound; i t i s the p r i n c i p a l commercial source of tungsten as well as being used as a phosphor, s c i n t i l l a t o r , and host l a t t i c e f o r s o l i d s t a t e l a s e r s . Among i n o r g a n i c compounds, the luminescence p r o p e r t i e s of s c h e e l i t e s have been s t u d i e d e x t e n s i v e l y . The ab s o r p t i o n and emission spect r a of the i n d i v i d u a l a l k a l i n e e a r t h molybdate and tungstate s a l t s as well as t h e i r mixed c r y s t a l s was reported by Kroger [111] as part of an extensive study on luminescent inorganic s o l i d s . The currently accepted model [112,113] for absorption and emission i n calcium tungstate i s that the intense e m i s s i o n band a t 420 nm i s due to a charge t r a n s f e r t r a n s i t i o n w i t h i n the tungstate anion. This model may be a p p l i e d to other compounds c o n t a i n i n g the tungstate or molybdate anions [114-118]. In t h i s study, sample powders of molybdate and tungstate s a l t s held i n quartz t e s t tube c e l l s were excited at 193 and 248 nm, the time-wavelength resolved luminescence s p e c t r a were c o l l e c t e d with the apparatus d e s c r i b e d i n 1 0 0 ' '93 c^<3, 1 n 7Qj Figure 4.2 Luminescence spectra, 193 nm excit a t i o n , 350 to 700 nm. (a) Calcium molybdate, 1000 ns to 20000 ns. (b) Calcium tungstate, 1 000 ns to 20000 ns. (c) Strontium molybdate, 100 ns to 2000 ns. (d) Strontium tungstate, 100 ns to 2000 ns. 1 02 Figure 4.3 Luminescence spectra, 248 nm excitation, 350 to 700 nm. (a) Calcium molybdate, 1000 ns to 20000 ns. (b) Calcium tungstate, 1 000 ns to 20000 ns. (c) Strontium molybdate, 100 ns to 2000 ns. (d) Strontium tungstate, 100 ns to 2000 ns. 1 03 chapter 2. The background luminescence from the quartz c e l l i s shown i n Figure 4.1. Under 193 nm exci t a t i o n the quartz c e l l luminesces s t r o n g l y with a very broad short l i f e t i m e emission and a long l i v e d band at 390 nm. E x c i t a t i o n a t 248 nm produces intense, long l i f e t i m e emission at 390 nm and a minor short l i f e t i m e band i n the 600 nm region. The long l i f e t i m e emission band at 390 nm i s l i k e l y due to trap s i t e s [119] present i n the quartz. The a l k a l i n e earth molybdates and tungstates having the s c h e e l i t e s t r u c t u r e were examined. The barium s a l t s p r e p a r e d had l i f e t i m e s l e s s than 50 ns and c r e d i b l e measurements could not be made due to the technical problems d e s c r i b e d i n c h a p t e r 2. S p e c t r a f o r the c a l c i u m and strontium s a l t s are shown i n Figures 4.2 and 4.3 for 193 nm and 248 nm e x c i t a t i o n r e s p e c t i v e l y . The spectra shown i n Figure 4.2 were smoothed for v i s u a l display. The emission band positions, halfwidths, and l i f e t i m e s were independent of the e x c i t a t i o n wavelengths used. However, the luminescence i n t e n s i t i e s appeared to be depen-dent on exc i t a t i o n wavelength. Absolute luminescence inten-s i t y measurements were not made due to l i m i t a t i o n s imposed by the spectrometer and e x c i t a t i o n source. The emission bands from both tungstate and molybdate were affected by the c a t i o n . The peak maxima p o s i t i o n s were s i m i l a r f o r both c a l c i u m and strontium compounds. The bandwidths f o r the strontium s a l t s were about 20% wider than those of the calci u m s a l t s . The calcium s a l t s had l i f e t i m e s about 20 104 t i m e s g r e a t e r than the c o r r e s p o n d i n g stronti>um s a l t . Assuming that t h i s trend continues on for the barium s a l t s , t h e i r expected l i f e t i m e s would be on the order of 10 ns. This appears to agree with observations made i n previous attempts to measure luminescence on barium s a l t s [82]. Zinc and cadmium s a l t s were a l s o examined. T h e i r s p e c t r a a re shown i n F i g u r e s 4.4 and 4.5 f o r 193 nm ex c i t a t i o n and 248 nm e x c i t a t i o n respectively. The spectra i n F i g u r e 4.4 were smoothed f o r v i s u a l d i s p l a y . The measurements on zinc molybdate appear to be due e n t i r e l y to the quartz c e l l (Figure 4.1). Cadmium molybdate e x h i b i t e d weak luminescence under both e x c i t a t i o n wavelengths. The most notable f e a t u r e i s that the c h a r a c t e r i s t i c molybdate peak maxima i s s h i f t e d to about 580 nm. The tungstate emission bands showed a s i m i l a r s h i f t with t h e i r peak maxima going to about 480 nm. The zinc and cadmium compounds peak maxima, halfwidths, and l i f e t i m e s appeared to be independent of e x c i t a t i o n wavelength. Both compounds showed gr e a t e r luminescence i n t e n s i t y under 193 nm e x c i t a t i o n . The z i n c tungstate band h a l f w i d t h was about 15% wider than the cadmium compound. Zinc and cadmium tungstate [120,121] have the wolframite structure. The difference i n tungstate and molybdate peak maxima p o s i t i o n s of the z i n c and cadmium s a l t s when compared to the a l k a l i n e earth compounds i s p r i n c i p a l l y due to the d i f f e r e n t c r y s t a l s t r u c t u r e s f o r these compounds. Results for the parameters describing the luminescence 105 Figure 4 . 4 Luminescence spectra, 193 nm excitation, 350 to 700 nm. (a) Zinc molybdate, 100 ns to 2000 ns, (b) Zinc tungstate, 1000 ns to 20000 ns, (c) Cadmium molybdate, 100 ns to 2000 ns, (d) Cadmium tungstate, 1000 ns to 20000 ns. 106 Figure 4.5 Luminescence spectra, 248 nm excitation, 350 to 700 nm. (a) Zinc molybdate, 100 ns to 2000 ns, (b) Z i n c t u n g s t a t e , 100 ns t o 2000 ns, (c) Cadmium molybdate, 100 ns to 2000 ns, (d) Cadmium tungstate, 1000 ns to 20000 ns. 1 07 from the s i n g l e molybdate and tungstate s a l t s e x c i t e d at 193 nm are summarized i n Table VI. N a t u r a l l y o c c u r r i n g substances such as minerals are r a r e l y found as pure compounds; i n v a r i a b l y they c o n t a i n contaminants of various composition and concentration. If two d i f f e r e n t compounds have the same or s i m i l a r c r y s t a l l i n e form they are s a i d to be isomorphous. The tungstate and molybdate ions are of s i m i l a r s i z e and they tend to form d i r e c t replacements f o r each other i n c r y s t a l l a t t i c e s to form an isomorphic series of compounds. The substitution of molybdate f o r tungstate i s common i n n a t u r a l l y o c c u r r i n g scheelite. This isomorphous substitution of molybdate for tungstate i s r e f l e c t e d i n luminescence observed [122,123] from the scheelite-powellite series, Ca(Mo,W)04, associated with v a r i o u s ore d e p o s i t types. A s i m i l a r e f f e c t has been r e p o r t e d [124,125] f o r the w u l f e n i t e - s t o l z i t e s e r i e s Pb(Mo,W)04. In these r e p o r t s , the common obs e r v a t i o n i s that when molybdate s u b s t i t u t i o n f o r tungstate approaches the 10% l e v e l , tungstate emission vanishes and the system exhibits luminescence c h a r a c t e r i s t i c of molybdate. Two isomorphous s e r i e s were prepared: Ca(Mo,W)C>4 and Sr(Mo,W)04. The s p e c t r a observed f o r these compounds are shown i n F i g u r e s 4.6, 4.7, and 4.8. The calcium molybdate-tungstate s e r i e s i n F i g u r e 4.6 was excited at 193 nm. The most s t r i k i n g feature shown i n t h i s s e r i e s i s that the tungstate l i f e t i m e i s a p p r e c i a b l y shortened by r e l a t i v e l y small quantities of molybdate. The 1 08 Table VI Spectral Parameters for Molybdate and Tungstate Salts Compound Lifetime Peak maxima Peak halfwidth US c m - ^ c m - ^ CaMoC>4 9.7 19210 6950 SrMo0 4 0.75 1 9430 7770 CdMo04 0.33 18350 6430 CaW04 8.6 24110 6330 SrW04 0.48 23920 7420 ZnW04 15.8 211 04 6150 CdW04 13.9 20670 5780 PbW04 1.9 23800 121 00 109 Figure 4.6 Luminescence spectra, 193 nm excitation, 1000 ns to 20000 ns, 350 nm to 700 nm. (a) CaW04, (b) Ca(Mo.02 W.98)04,(c) C a ( M o j W.g)04f (d) Ca(Mo f 2 W. 8)0 4, (e) Ca(Mo. 3 W. 8)0 4, (f) CaMo0 4. 11 0 Figure 4.7 Luminescence spectra, 193 nm excitation, 100 ns to 2000 ns, 350 nm to 700 nm. (a) SrW0 4, (b) S r ( M o o 2 w 9 8 ) ° 4 ' ( c ) S r ( M o -j W 9 ) 0 4 , (d) Sr(Mo] 2 W#8*)04, (e) Sr(Mo # 3 W > 8)0 4,*(f) SrMo0 4. 111 SrU04 - KrF SHMo.02 W.98)04 - KrF Sr(MO.05 W.95J04 - KrF Sr(Mo.2 W.8)04 - KrF Sr(Mo.3 V.7J04 - KrF SrMo04 - KrF Figure 4.8 Luminescence spectra, 248 nm excitation, 100 ns to 2000 ns, 350 nm to 700 nm. (a) SrW0 4 / (b) Sr(Mo 02 W 9 8 ) 0 4 , ( c ) S r ( M o j W > 9 ) 0 4 , (d) Sr(Mo[ 2 w f 8*)04, (e) S r ( M o j W > 8)0 4, (f) SrMo0 4. 112 quenching e f f e c t i s somewhat understated i n the d i s p l a y format used; the i n t e n s i t y of pure calcium molybdate i s approximately one e i g h t h that of pure calcium tungstate. S i m i l a r behavior i s observed f o r the strontium molybdate-tungstate series excited at 193 nm as i l l u s t r a t e d i n Figure 4.7. The trend i n the strontium s e r i e s i s s i m i l a r to that of the c a l c i u m s e r i e s , w i t h the quenching e f f e c t of molybdate being even more pronounced. The strontium s e r i e s e x c i t e d at 248 nm was examined; the s e r i e s s p e c t r a are presented i n Figu r e 4.8. Again, the quenching p a t t e r n i s s i m i l a r with the e f f e c t of molybdate being even more pronounced. In t h i s s e r i e s , molybdate luminescence dominates when present at le v e l s less than 5%. Tungstate luminescence l i f e t i m e i s related to molybdate c o n c e n t r a t i o n as i l l u s t r a t e d i n the p l o t s i n F i g u r e 4.9. The two isomorphous series were excited at 193 nm, and the l i f e t i m e information was extracted from the time-wavelength resolved spectra using the data reduction program l i s t e d i n Appendix 4. The r e l a t i o n s h i p shown between l i f e t i m e and molybdate concentration i s empirical without appeal to any s p e c i f i c energy transfer model. The quenching e f f e c t s seen i n these isomorphous series demonstrate the advantage of t a k i n g the m u l t i d i m e n s i o n a l approach of time-wavelength resolved luminescence to extract ad d i t i o n a l information from the luminescence signal. This approach affords a more comprehensive understanding of the processes occurring i n the system under study, which i n turn 113 1 1 1 1 1 1 r r ] - 4 - 3 - 2 - 1 I 1 2 3 4 1n(Mo/V) b T 1 1 2 InCMo/V) 4.9 R e l a t i o n s h i p between tungstate l i f e t i m e and molybdate to tungstate r a t i o i n mixed c r y s t a l s , 193 nm e x c i t a t o n . (a) Sr(Mo,W)C>4 system, (b) Ca(Mo,W)04 system. 11 4 leads to a more robust a n a l y t i c a l scheme. 4.3 ZIRCONATES AND HAFNATES Zirconium and hafnium have the most s i m i l a r chemistries of a l l elements i n the p e r i o d i c chart. This s i m i l a r i t y i s e x h i b i t e d both i n t h e i r n a t u r a l occurrence [89] and the extreme d i f f i c u l t i e s i n t h e i r s e p a r a t i o n and a n a l y s i s by c h e m i c a l t e c h n i q u e s . Both e l e m e n t s form e x t e n s i v e isomorphous series of compounds with each other. Atomic and mass spectroscopy are the most robust a n a l y t i c a l techniques for the i d e n t i f i c a t i o n and quantitation of these elements. Very l i t t l e work has been reported i n the l i t e r a t u r e on the luminescence properties of the a l k a l i n e earth zirconates and there are no reports on a l k a l i n e earth hafnate lumines-cence. The most r e l i a b l e reports of zirconate luminescence are for mixed zirconium-silicon oxides [126-128], although trace titanium may have been the activator i n the Gaft [126] and Lysakov [127] r e p o r t s . Blasse [129] s t a t e s that, f o r the weakly luminescent BaZrSi30g, e x c i t a t i o n i s p o s s i b l e only f o r wavelengths less than 220 nm. The p r o p e r t i e s of calcium z i r c o n a t e as a host l a t t i c e f o r a c t i v a t o r s such as lead [130], manganese [131], and t r i v a l e n t lanthanides [132] have been reported. However, no mention was made i n these reports on the l e v e l s of hafnium present i n the calcium zirconate host l a t t i c e . The a l k a l i n e earth zirconates and hafnates used i n t h i s study were prepared from u l t r a p u r e z i r c o n a t e and hafnate s t a r t i n g m a t e r i a l s as o u t l i n e d i n chapter 2.° I n i t i a l 115 attempts to measure luminescence spect r a on the undoped compounds held i n the quartz t e s t tube c e l l s were unsuc-c e s s f u l due to a combination of strong luminescence from the quartz c e l l s and very weak luminescence from the compounds examined. A sample c o n s i s t i n g of two S u p r a s i l d i s c s , clamped together to hold sample powders, was sat i s f a c t o r y . The S u p r a s i l d i s c s were weakly luminescent under e i t h e r 193 nm or 248 nm excitation. Their time-wavelength resolved luminescence s p e c t r a are shown i n Fig u r e 4.10. The time-wavelength r e s o l v e d s p e c t r a f o r pure and doped a l k a l i n e earth zirconates, hafnates, and oxides appear at the end of thi s chapter. Contamination of the zirconate and hafnate powders with al k a l i n e earth oxide was a d i s t i n c t p o s s i b i l i t y , even though t h e i r presence was not i n d i c a t e d i n the X-ray powder data. Spectra measured f o r the pure and doped a l k a l i n e earth oxides are included for comparison. Attempts to e x t r a c t s p e c t r a l parameters from data coll e c t e d on the pure a l k a l i n e earth zirconates and hafnates w i t h the a l g o r i t h m and model d e s c r i b e d e a r l i e r were unsuccessful. Luminescence decay does not appear to follow s i m p l e f i r s t o r d e r k i n e t i c s . T h i s may be due to the presence of s e v e r a l e m i t t i n g components or to energy migration e f f e c t s . The observed luminescence decay i s rapid and instrumental l i m i t a t i o n s may be responsible for apparent n o n - f i r s t order decay behavior. The pure a l k a l i n e earth zirconates and hafnates do not 116 appear to luminesce at wavelengths greater than 270 nm when e x c i t e d at 193 nm. However, under 248 nm e x c i t a t i o n a prominent band centered i n the 500 nm region appears along with a long l i v e d band at 650 nm. The 650 nm band may be due to l a t t i c e defects or trace quantities of a l k a l i n e earth oxide present. The band i n the 500 nm region shows changes i n p o s i t i o n , width, and l i f e t i m e among the d i f f e r e n t compounds i n v e s t i g a t e d . F u r t h e r e x p l o i t a t i o n of the data contained i n these spectra i s dependent on having a suitable data reduction process. The e f f e c t s of dopants added to the a l k a l i n e e a r t h z i r c o n a t e s and hafnates was i n v e s t i g a t e d . G e n e r a l l y , the added a c t i v a t o r dominates the o b s e r v e d l u m i n e s c e n c e spectrum. Few differences were observed i n the wavelength domain between e x c i t a t i o n at 193 nm and 248 nm among the compounds studied. However, i n the time domain some s t r i k i n g e f f e c t s were observed. In the lead a c t i v a t e d compounds, the l i f e t i m e of the band a s s o c i a t e d w i t h l e a d was markedly dependent on e x c i t a t i o n wavelength. This phenomenon was observed f o r a l l the a l k a l i n e earth zirconates and hafnates studied without exception. In the b i s m u t h a c t i v a t e d compounds, e x c i t a t i o n wavelength dependent e f f e c t s on the emission c h a r a c t e r i s t i c to bismuth were a l s o observed. In t h i s case, the e f f e c t s appear to be more cl o s e l y correlated with the a l k a l i n e earth ion rather than zirconate or hafnate. 117 In the t h a l l i u m and antimony a c t i v a t e d compounds, e x c i t a t i o n wavelength dependent e f f e c t s were noted but re a d i l y d i s c e r n i b l e patterns were not seen. The d i f f e r e n t i a t i o n between z i r c o n a t e and hafnate i n inorganic powders by time-wavelength resolved luminescence appears possible i n simple systems such as the calcium and strontium compounds as can be seen i n comparing Figures 4.12 (a) w i t h 4.24 (a) and F i g u r e s 4.16 (a) w i t h 4.28 (a). 118 (D X O H-f t r t o 3 CO 3 3 CD X o o r t 3 0 rt 0 ~-j on vo o 3 3 § r t • 0 On 3 h (D 3 - > B 3 0 3 • o ^ j O h PJ cr 3 01 _> * 1 - 1 Di OJ (U p. 3 W W 3 - ° u-, OJ 3 3 H-3 CD CO O CD 3 O CD CO tJ CD O to f t cn " X O H-rt (u rt OJH-o O o 3 r t O X Z D I S I $ SUPRflSIL DISCS XZDISC-1 $ SUPRflSIL DISCS XNCZTL-3 Tl lHBppa firf XNCZSB-1 S CeZrO 1020ppn flrF Figure 4.11 Calcium zirconate; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 270 nm to 760 nm (b) T l doped, 500 ns to 10000 ns, 300 nm to 790 nm (c) Sb doped, (d) Pb doped, (e) Bi doped, 50 ns to 1000 ns, 300 nm to 790 nm 50 ns to 1 000 ns, 300 nm to 790 nm 50 ns to 1000 ns, 300 nm to 790 nm 120 ^ ^ ^ ^ ^ Figure 4.12 Calcium zirconate; excitation: 193 nm. (a) no dopant, 50 ns to 1 000 ns, 265 nm to 570 nm (b) T l doped, 500 ns to 10000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 510 nm (d) Pb doped, 50 ns to 1000 ns, 265 nm to 510 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 510 nm 121 Figure 4.13 Calcium zirconate; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 50 ns to 1000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1000 ns, 300 nm to 790 nm 122 Figure 4.14 Calcium zirconate; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 510 nm (b) T l doped, 50 ns to 1 000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 51 0 nm (d) Pb doped, 50 ns to 1 000 ns, 265 nm to 51 0 nm (e) Bi doped, 50 ns to 1 000 ns, 265 nm to 510 nm 123 Figure 4.15 Strontium zirconate; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1000 ns, 300 nm to 700 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 50 ns to 1 000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1 000 ns, 300 nm to 790 nm 124 Figure 4.16 Strontium zirconate; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 510 nm » / £ I — - — v ' ~ " / — »•••• WW • (b) T l doped, 50 ns to 1000 ns, 270 nm to 420 (c) Sb doped, 50 ns to 1000 ns, 265 nm to 510 (d) Pb doped, 50 ns to 1000 ns, 265 run to 510 (e) Bi doped, 50 ns to 1000 ns, 265 nm to 510 nm nm nm nm 125 Figure 4.17 Strontium zirconate; excitation: 248 nm. (a) no dopant, 50 ns to 1 000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1 000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1 000 ns, 300 nm to 700 nm (d) Pb doped, 50 ns to 1000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1 000 ns, 300 nm to 700 nm 126 Figure 4.18 Strontium zirconate; e: (a) no dopant, 50 ns tc (b) T l doped, 50 ns to (c) Sb doped, 50 ns to (d) Pb doped, 50 ns to c i t a t i o n : 248 nm. 1000 ns, 300 nm to 545 nm 1 000 ns, 265 nm to 510 nm 1000 ns, 300 nm to 545 nm 1000 ns, 265 nm to 510 nm 127 Figure 4.19 Barium zirconate; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1 000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 50 ns to 1 000 ns, 300 nm to 700 nm (e) Bi doped, 50 ns to 1000 ns, 300 nm to 790 nm 128 Figure 4.20 Barium zirconate; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 510 nm (b) T l doped, 50 ns to 1000 ns, 265 nm to 51 0 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 51 0 nm (d) Pb doped, 50 ns to 1 000 ns, 265 nm to 500 nm (e) Bi doped, 50 ns to 1 000 ns, 265 nm to 51 0 nm 129 Figure 4.21 Barium zirconate; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 700 nm (d) Pb doped, 50 ns to 1000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1000 ns, 300 nm to 700 nm 130 Figure 4.22 Barium zirconate; excitation: 248 nm. (a) no dopant, 50 ns to 1 000 ns, 265 nm to 51 0 nm (b) T l doped, 50 ns to 1 000 ns, 265 nm to 51 0 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 51 Onm (d) Pb doped, 50 ns to 1 000 ns, 300 nm to 545 nm (e) Bi doped, 50 ns to 1 000 ns, 265 nm to 51 0 nm 131 Figure 4.23 Calcium hafnate; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nr (b) T l doped, 50 ns to 1 000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 50 ns to 1 000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1 000 ns, 300 nm to 790 nm 132 excitation: 193 nm. 133 (a) no dopant, 50 ns to 1000 ns, (b) T l doped, 50 ns to 1000 ns, (c) Sb doped, 50 ns to 1000 ns, (d) Pb doped, 50 ns to 1 000 ns, (e) Bi doped, 50 ns to 1 000 ns, 134 XVCH-2 J CoHf03 1871222) - KrF Figure 4.26 Calcium hafnate; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 51 0 nm (b) T l doped, 50 ns to 1000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 51 0 nm (d) Pb doped, 50 ns to 1 000 ns, 265 nm to 51 0 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 51 0 nm 135 Figure 4.27 Strontium hafnate; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1 000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1 000 ns, 300 nm to 790 nm <d) Pb doped, 50 ns to 1 000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1000 ns, 300 nm to 790 nm 136 Figure 4.28 Strontium hafnate; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 500 nm (b) T l doped, 50 ns to 1000 ns, 265 nm to 500 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 500 nm (d) Pb doped, 50 ns to 1000 ns, 265 nm to 500 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 500 nm 137 XLSHTL-2 $ SrhTMtYn lB00pp» Krf XMSHSB-5 $ SrHf03:.Sb lBBBppm Krf XMSrPB-6 $ SrHfOlPb lBBBppa Krf XLSrBI-2 $ SrHf03/tel lBBBppm Krf Figure 4.29 Strontium hafnate; excitation: (a) no dopant, 50 ns to 1000 ns, 50 ns to 1000 ns, 50 ns to 1000 ns, (b) (c) (d) (e) T l Sb Pb Bi doped, doped, doped, doped, 248 nm. 300 nm to 700 nm 300 nm to 790 nm 300 nm to 790 nm 2000 ns to 40000 50 ns to 1000 ns, ns, 350 300 nm nm to to 700 790 nm nm 138 XHStf'B-S $ SrHfOlPb 1000pp. KrF XLSHBI-3 I lB00ppm KrF Figure 4.30 Strontium hafnate; excitation: 248 nm. (a) no dopant, 100 ns to 2000 ns, 300 nm to 545 nm (b) T l doped, 50 ns to 1000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 545 nm (d) Pb doped, 50 ns to 1000 ns, 300 nm to 545 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 500 nm 139 Figure 4.31 Barium hafnate; excitation: 193 nm. 300 nm to 790 nm 300 nm to 790 nm 300 nm to 790 nm 300 nm to 790 nm 300 nm to 790 nm (a) no dopant, 50 ns to 1 000 ns, (b) T l doped, 50 ns to 1 000 ns, (c) Sb doped, 50 ns to 1000 ns, (d) Pb doped, 50 ns to 1 000 ns, (e) Bi doped, 50 ns to 1000 ns, 140 XOBH-1 S BaHf03 (671222) - frf Figure 4.32 Barium hafnate; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 510 nm (b) T l doped, 50 ns to 1 000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1 000 ns, 265 nm to 51 0 nm (d) Pb doped, 50 ns to 1 000 ns, 265 nm to 510 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 51 0 nm 141 Figure 4.33 Barium hafnate; ex c i t a t i o n : 248 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1 000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 50 ns to 1 000 ns, 300 nm to 790 nm (e) B i doped, 50 ns to 1 000 ns, 300 nm to 790 nm 142 Figure 4.34 Barium hafnate; excitation:. 248 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 510 nm (b) T l doped, 50 ns to 1000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 510 nm (d) Pb doped, 50 ns to 1000 ns, 265 nm to 510 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 510 nm 143 XTCfl-3 $ CeO I8BB129) - ftrf Figure 4.35 Calcium oxide; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1 000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 50 ns to 1 000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1 000 ns, 300 nm to 790 nm 144 Figure 4.36 Calcium oxide; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 510 nm (b) T l doped, 50 ns to 1000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 510 nm (d) Pb doped, 50 ns to 1000 ns, 265 nm to 510 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 510 nm 145 Figure 4.37 Calcium oxide; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 50 ns to 1000 ns, 300 nm to 795 nm (e) B i doped, 50 ns to 1000 ns, 300 nm to 790 nm 146 Figure 4.38 Calcium oxide; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 510 nm (b) T l doped, 50 ns to 1 000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 510 nm (d) Pb doped, 50 ns to 1000 ns, 265 nm to 51 0 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 510 nm 147 (880201) - firr" Figure 4.39 Strontium oxide; ex c i t a t i o n : 193 nm. (a) no dopant, 100 ns to 2000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 100 ns to 2000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1000 ns, 300 nm to 790 nm 148 Figure 4.40 Strontium oxide; excitation: 193 nm. (a) T l doped, 50 ns to 1000 ns, 265 nm to 510 nm (b) Sb doped, 50 ns to 1000 ns, 265 nm to 510 nm (c) Pb doped, 50 ns to 1000 ns, 265 nm to 510 nm (d) Bi doped, 50 ns to 1000 ns, 265 nm to 510 nm 149 Figure 4.41 Strontium oxide; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns f 300 nm to 790 nm (b) T l doped, 50 ns to 1000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 50 ns to 1000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1000 ns, 300 nm to 790 nm 150 Figure 4.42 Strontium oxide; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 510 nm (b) T l doped, 50 ns to 1000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 510 nm (d) Pb doped, 50 ns to 1000 ns, 265 nm to 510 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 510 nm 151 Figure 4.43 Barium oxide; excitation: 193 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (c) Pb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) T l doped, 50 ns to 1000 ns, 300 nm to 790 nm 152 XUBRTL-1 S BotkTI lBBBppn - flrF XUBRSB-1 S BoO: 5b 1000ppi» flrF XUBRPB-2 Pb lBBBppn - flrF XUBflBM $ BeOBl lBBBppn - RrF Figure 4 . 4 4 Barium oxide; excitation: 193 nm. (a) no dopant, 100 ns to 1000 ns, 265 nm to 510 nm (b) T l doped, 50 ns to 1000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1000 ns, 265 nm to 510 nm (d) Pb doped, 100 ns to 1000 ns, 265 nm to 510 nm (e) B i doped, 50 ns to 1000 ns, 265 nm to 510 nm 153 Figure 4.45 Barium oxide; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns, 300 nm to 790 nm (b) T l doped, 50 ns to 1 000 ns, 300 nm to 790 nm (c) Sb doped, 50 ns to 1000 ns, 300 nm to 790 nm (d) Pb doped, 50 ns to 1000 ns, 300 nm to 790 nm (e) Bi doped, 50 ns to 1000 ns, 300 nm to 790 nm 154 Figure 4.46 Barium oxide; excitation: 248 nm. (a) no dopant, 50 ns to 1000 ns, 265 nm to 51 0 nm (b) T l doped, 50 ns to 1000 ns, 265 nm to 510 nm (c) Sb doped, 50 ns to 1 000 ns, 265 nm to 51 0 nm (d) Pb doped, 50 ns to 1 000 ns, 265 nm to 510 nm (e) Bi doped, 50 ns to 1000 ns, 265 nm to 51 0 nm 155 Chapter 5 CONCLUDING REMARKS In t h i s study, the multidimensional approach of time-wavelength resolved luminescence spectroscopy was examined to see i f a n a l y t i c a l l y useful information could be extracted from the complex luminescence signals i n t r i n s i c to inorganic s o l i d s . The r e s u l t s presented i n t h i s t h e s i s c l e a r l y show the advantages inherent to t h i s approach. Information present i n the time-wavelength resolved spectrum allows the use of energy t r a n s f e r and energy m i g r a t i o n phenomena i n inorganic substance characterization. This i s p o t e n t i a l l y a very powerful a n a l y t i c a l t o o l s i n c e i t may be a p p l i e d to q u a n t i t a t i v e t r a c e a n a l y s i s as w e l l as to d e s c r i b i n g the gross structure of a substance. The s i m p l e m o l y b d a t e - t u n g s t a t e systems s t u d i e d i l l u s t r a t e the p o t e n t i a l of using energy t r a n s f e r i n the quantitative analysis of inorganic powders. The mechanism for energy transfer from tungstate to molybdate i s l i k e l y by a nonresonance radiationless route, since the decay appears to be f i r s t order for both molybdate and tungstate emission. Other modes of energy t r a n s p o r t and energy m i g r a t i o n i n s o l i d s may have i n t e r e s t i n g a n a l y t i c a l a p p l i c a t i o n s . For example, when energy m i g r a t i o n processes occur i n a host l a t t i c e , the decay l i f e t i m e may be a function of in d i v i d u a l p a r t i c l e s i z e . This phenomenon may be r e a d i l y a p p l i e d to the rapid, remote monitoring of p a r t i c l e size i n a m i l l i n g operation. 156 The degree of success of a multidimensional approach to luminescence spectroscopy i s markedly dependent on the data r e d u c t i o n operations employed. The two stage process employed i n t h i s study provided r e l i a b l e estimates for the number of components present and t h e i r parameters. This algorithm works well for up to three components. However, the computational burden becomes excessive f o r systems c o n t a i n i n g more than three components. For more complex systems, highly e f f i c i e n t d i g i t a l f i l t e r techniques appear to be the optimal solution. The adaptive Kalman f i l t e r i s an o p t i m a l approach f o r r e a l time data reduction. This powerful algorithm i s well suited to applying both empirical and t h e o r e t i c a l models to a data set. For example, a spectrum from an unknown material could be rapi d l y compared with empirical wavelength domain s p e c t r a while a p p l y i n g v a r i o u s models f o r the l u m i n e s c e n c e decay. T h i s type of d a t a t r e a t m e n t i s p a r t i c u l a r l y well suited to i n d u s t r i a l process control or to rapid screening tests on c l i n i c a l specimens. The lanthanides are p a r t i c u l a r l y i n t e r e s t i n g since t h e i r l i n e - l i k e s p e c t r a and p a r t i c i p a t i o n i n energy m i g r a t i o n c a r r y much i n f o r m a t i o n on the l o c a l and g l o b a l environments of a s o l i d . The m u l t i d i m e n s i o n a l approach p r o v i d e s r e l a t i v e l y easy a c c e s s t o t h i s i n f o r m a t i o n , p a r t i c u l a r l y when used i n c o n j u n c t i o n with s i t e s e l e c t i v e excitation. A potential a p p l i cation i s the nondestructive d e t e r m i n a t i o n of the d i s t r i b u t i o n of t r a c e lanthanides i n 157 c u l t u r a l a r t i f a c t s such as p o t t e r y , stone s c u l p t u r e , and paint pigments. The studies on zirconates and hafnates gave indications of short l i f e t i m e luminescence i n the near infrared. Very l i t t l e attention has been paid to near infrared luminescence from natural substances such as rocks and minerals. These m a t e r i a l s should produce r i c h e mission s p e c t r a due to the charge transfer absorption bands associated with iron ions i n many minerals and energy t r a n s f e r phenomena. Time-wavelength r e s o l v e d luminescence i n t h i s r e g i o n o f f e r s e x c i t i n g p o s s i b i l i t i e s f o r remote s e n s i n g s i n c e the atmosphere i s transparent for both e x c i t a t i o n and emission. The e x p l o r a t o r y work reported i n t h i s t h e s i s was subject to l i m i t a t i o n s imposed by the equipment available. Studies on energy transfer and energy migration require time domain measurements spanning the range from sub nanosecond to seconds. Multichannel spectral domain measurements are esse n t i a l for e f f i c i e n t data c o l l e c t i o n . For future work, a spectrometer c o n s i s t i n g of a polychromator with a gated, i n t e n s i f i e d d i o d e a r r a y d e t e c t o r i s r e q u i r e d . The e x c i t a t i o n source should be able to supply pulsed, high i n t e n s i t y r a d i a t i o n from the red to u l t r a v i o l e t regions. A convenient source would c o n s i s t of a pulsed tuneable dye laser coupled with a frequency multiplying c r y s t a l . The work presented i n t h i s thesis has shown that time-wavelength resolved luminescence i s a p o t e n t i a l l y valuable a n a l y t i c a l t o o l f o r the c h a r a c t e r i z a t i o n of luminescent 158 i n o r g a n i c s o l i d s . Thus, the o b j e c t i v e s of t h i s study have been met. H o p e f u l l y , the background i n f o r m a t i o n and experimental data presented i n t h i s t h e s i s w i l l s t i m u l a t e and encourage others to continue i n v e s t i g a t i o n s i n t h i s area. 1 59 REFERENCES 1 Harwit, M. Astrophysical Concepts; Wiley: New York, 1973. 2 Harvey, E. N. A History of Luminescence; American Philo-sophical Society: Philadelphia, PA, 1957. 3 Akasofu, S-I. S c i e n t i f i c American; 1965, 213(6), 54-62. 4 Weiner, J . Planet Earth; Bantam: Toronto, 1986, pp. 238-242. 5 Partington, J. R. 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P h y s . 1 9 8 2 , _42, 1 5 5 - 2 0 5 . 108 R u t a n , S . C ; B r o w n , S . D . A n a l . C h i m . A c t a 1 9 8 5 , 1 7 5 , 21 9 -2 2 9 . 109 K n o r r , F . J . ; H a r r i s , J . M . ; A n a l . C h e m . 1 981 , 53_, 2 7 2 - 2 7 6 . 110 K n o r r , F . J . ; T h o r s h e i m , H . R . ; H a r r i s , J . M . A n a l . C h e m . 1981 , 5 3 , 8 2 1 - 8 2 5 . 111 K r o g e r , A . Some A s p e c t s o f t h e L u m i n e s c e n c e o f S o l i d s ; E l s e v i e r : New Y o r k , 1 9 4 8 . 112 T r e a d a w a y , M . J . ; P o w e l l , R . C . J . C h e m . P h y s . 1 9 7 4 , 61 , 4 0 0 3 - 4 0 1 1 . 1 65 113 G u r v i t c h , A. M.; Gutan, V. B.; Meleshkin, B. N.; M i k h a i l i n , V. V.; Mikhalev, A. A.; Tombak, M. I. J. Lumin. 1 977, 1 5, 187-199. 114 I v a n o v s k i i , A. L.; Zhukov, V. P.; Slepukhin, V. K.; Gubanov, V. A.; Shveikin, G. P. Zh. Strukt. Khim. 1 980, 21_, 30-36. 115 Tyner, C. E.; Drickamer, H. G. J. Chem. Phys. 1 977, 67, 4103-4115. 116 Van Loo, V. J . Lumin. 1 975, 1_0, 221-235. 117 Blasse, G.; Van den Heuvel, G. P. M. J. Lumin., 1 974, 9_, 74-78. 118 Grasser, R.; Scharmann, A. J . Lumin. 1976, 12/13, 473-478. 119 Wong, J,; Angell, C. A. Glass Structure by Spectroscopy; Marcel Dekker: New York, 1976. 120 Wyckoff, R. W. G. Crystal Structures, 2nd. ed.; Inter-science: New York, 1 965, Vo l . 3, pp. 41-43. 121 Palache, C; Berman, H.; Fronel, C. The System of  Mineralogy, 7th. ed.; Wiley: New York, 1951, Vol. I I , pp. 1064-1071. 122 Gorobets, B. S.; N a u c h i t e l , M. A. K o n s t i t u t s i i a i S v o i s t v a  Mineralov, 1 975, 9_, 98-1 05. 123 Nauchitel, M. A. Zakonomren. Raspred. Primesnykh Tsentrov  Ionnykh K r i s t . 1974, 3, 71-79. 124 Efendiev, Sh. M; Darvishov, N. G.; Gabrielyan, V. T. Phys.  Stat. Sol. A 1984, 86, K105-K108. 125 Darvishov, N. G.; Godzhaeva, Sh. M.; Efendiev, Sh. M.; Yusifov, F. K. ; Deposited Doc. 1984, VINITI 1678-84, 12pp. 126 Gaft', M. L.; Gorobets, B. S.; Khomyakov, A. P. Dokl. Akad.  Nauk SSSR 1981, 260, 1234-1237. 127 Lysakov, V. S.; Solntsev, V. P.; E l i s e e v , A. P. Zh. P r i k l .  Spektrosk. 1976, 25, 823-826. 128 Blasse, G.; B r i l , A. J . S o l i d State Chem. 1970, 2, 105-108. 129 Blasse, G. Structure and Bonding 1980, 42, 1-41. 130 Braam, A. W.; Blasse, G. S o l i d State Commun. 1 976, 2_0, 717-71 9. 131 Blasse, G.; De Korte, P. H. M. J. Inorg. Nucl. Chem. 1 981 , 43, 1505-1506. 1 66 132 Kravets, N. V.; Zakharov, V. M.; Polezhaev, Yu. M.; Kruzhalov, A. V.; Shul'gin, B. V. Zh. F i z . Khim. 1 978 1810. 133 Wyckoff, R. w. G. Crystal Structures, 2nd. ed.; Inter s c i e n c e : New York, 1 965, V o l . 2, pp. 390-402. 1 67 A P P E N D I X 1 SPECTROMETER CONTROL PROGRAM I N B A S I C 1 'PROGRAM ZAPIT-9C - REVISION 7.6 - 870826 - USES ISOLATION RELAY 2 'BY E. F. PASKI * (C) COPYRIGHT 1987 * ALL RIGHTS RESERVED 3 'ACQUISITION PROGRAM FOR CORONA - BOXCAR - MONOCHROMATOR - PEAK DETECTOR • 10 'MONOCHROMATOR DRIVER ROUTINE IN MACHINE LANGUAGE 11 CLEAR,&HFFOO : DEF SEG : DEF USRO=&HFF0O 12 FOR I%=&HFFOO TO &HFFFF : POKE I%,0 : NEXT 1% 'INITIALIZE MEMORY 13 'READ AND STORE MONOCHROMATOR DRIVER PROGRAM 14 FOR I%=&HFFOO TO &HFF45 : READ X% : POKE I%,X% : NEXT 1% 15 DATA &HB8 f MO,MO f m3,^2 t &HFF t MFF,ff l06 ,^2 t f im 16 DATA &HB0.&H7F.&HEE 17 DATA m8,^ 0,&H0>&HA3,&HF6,&HFF,&HFF,&H06,&HF6,&HFF,&HBE,&HF4,&HFF 18 DATA &HBF,&HF6,&HFF,&HA7,&H75,&HF3 19 DATA &HBA,&HBC,&H03,&HB0,&H7E,&HEE 20 DATA B^8,^ 0>&H0,&HA3,&HF6,&HFF,&HFF,&H06,&HF6,&HFF,&HBE,&HF4,&HFF 21 DATA &HBF,&HF6,&HFF,&HA7,&H75,&HF3 22 DATA mE,&HF0,SJIFF,&HBF,&HF2,&HFF,&HA7,&H75,&HCl,&HCB 23 POKE &HFFF0,&H1 : POKE &HFFF1.&H0 'MINIMUM TOGGLES ON PORT 24 POKE &HFFF4.&H10 : POKE &HFFF5.&H0 'CONTROLS WAIT PERIOD 70 H0ME$=CHR$(12) LF$=CHR$(10) : BELL$=CHR$(7) : QT$=CHR$(34) KEY OFF 90 NHITS%=6 '# LASER SHOTS PER DATA POINT 100 DIM HIT(IOO), SH0T(200,1), LUMIN(100,10), REFER(100,10) 200 PRINT HOME$; BELL$ 300 ' 301 PRINT H0ME$;"FILE HEADER DATA " 310 INPUT"FILE NAME ";FILENAME$ : IF INSTR(FILENAME$,".") THEN 315 311 IF FILENAME$="" THEN FILENAME$="TESTTEST.LCD" 313 FILENAME$=LEFT$(FILENAME$,8)+".LCD" 315 PRINT : LINE INPUT"SUBSTANCE ";SUBSTANCE$ : IF SUBSTANCE$="" THEN SUBSTANCE$="**" 320 PRINT : LINE INPUT"MISCELLANY ";MISC$ : IF MISC$="" THEN MISC$="***" 330 PRINT : INPUT"WAVELENGTH (ANGSTROMS) TO START SCAN "; LAMSTART% : IF LAMSTART%=0 THEN LAMSTART%=1 331 PRINT LAMSTART% 335 PRINT : INPUT"WAVELENGTH (ANGSTROMS) TO END SCAN "; LAMEND% : IF LAMEND%=0 THEN LAMEND%=1 336 PRINT LAMEND% 168 340 PRINT : INPUT'WAVELENGTH (ANGSTROMS) STEPS FOR SCAN "; LAMSTEP% : IF LAMSTEP%=0 THEN LAMSTEP%=1 341 PRINT LAMSTEP% 350 PRINT : INPUT'CURRENT WAVELENGTH ON MONOCHROMATOR (ANGSTROMS) "; ANGORIGIN% : IF ANGORIGIN%=0 THEN ANG0RIGIN%=1 351 PRINT ANGORIGIN% 352 ANGEND%=ANGORIGIN% 360 PRINT : INPUT'BOXCAR WINDOW WIDTH, MICROSECONDS (DEFAULT=1)*';WINWIDE : IF WINWIDE=0 THEN WINWIDE=1 361 PRINT WINWIDE 370 PRINT : INPUT'NUMBER OF WINDOWS AT EACH WAVELENGTH (DEFAULT=5)";NWIND0WS% : IF NWIND0WS%>100 THEN PRINT BELL$;"MAXIMUM ALLOWED IS 100" : GOTO 370 371 IF NWIND0WS%<1 THEN NWIND0WS%=5 375 PRINT NWINDOWS% 380 PRINT : INPUT"GATE DELAY MULTIPLIER [MAX:=10; VALUE*0.1] (DEFAULT=1)";GATEMUL : IF (GATEMUL*NWIND0WS%)>100 THEN PRINT BELL$ : PRINT"MUST HAVE: 100 > WINDOWS * GATEMUL!" : GOTO 380 381 IF GATEMUL=0 THEN GATEMUL=1 382 PRINT GATEMUL 385 DVOLTS=GATEMUL*.1 390 PRINT : INPUT'DELAY SCALE SETTING, IN MICROSECONDS (DEFAULT=10) ";DELAYSCALE : IF DELAYSCALE=0 THEN DELAYSCALE=10 395 PRINT DELAYSCALE 400 PRINT LF$;LF$;LF$;BELL$ : PRINT"ENSURE THAT SAMPLE IS PROPERLY MOUNTED AND LASER IS READY";LF$ : PRINT"ENTER ";QT$;"GO";QT$;" TO COMMENCE EXPERIMENT" 410 INPUT A$ : IF NOT(A$="GO" OR A$="go") THEN 400 1000 'OPEN FILE FOR SERIAL PORT, SETUP BOXCAR INTERFACE 1010 GOSUB 10200 : GOSUB 10300 1030 'OPEN SEQUENTIAL TEXT FILE FOR DATA 1040 OPEN "0",2,FILENAME$ 1050 PRINT#2, FILENAME$ : PRINT#2, SUBSTANCE$ : PRINT#2, MISC$ : PRINT#2, TIME$ : PRINT#2, DATE$ : PRINT#2, DELAYSCALE : PRINT#2, DVOLTS 1052 PRINT#2, NHITS% : PRINT#2, NWINDOWS% : PRINT#2, LAMSTART% : PRINT#2, LAMEND% : PRINT#2, LAMSTEP% : PRINT#2, WINWIDE 1060 CLOSE 2 169 1100 'CAPTURE ONE SET OF SPECTRA, N READINGS AT EACH OF M WAVELENGTHS 1110 FOR LAMDA%=LAMSTART% TO LAMEND% STEP LAMSTEP% 1120 PRINT"SLEWING TO ";LAMDA%;" ANGSTROMS" : ANGSTART%=ANGEND% : ANGEND%=LAMDA% : GOSUB 10100 1200 'COLLECT A DECAY CURVE AT THIS WAVELENGTH 1210 'SET DELAY TIME N BOXCAR note - at default setting of lOus on DELAY SCALE, : lO.OOOv = lOOus and time delay steps are in : O.lOOv increments which becomes l.Ous steps. 1220 GOSUB 10800 : GOSUB 10800 1230 FOR NSH0T%=1 TO NWIND0WS% 1240 DY$="S8="+STR$(DV0LTS*NSH0T%) 1250 PRINT#1, DY$ 1260 FOR I%=1 TO NHITS% 1270 GOSUB 10800 1272 LUMIN(NSHOT%,I%)=VAL(LUM$) : REFER(NSH0T%,I%)=VAL(REF$) 1280 HIT(I%)=VAL(VALUE$) 1285 IF HIT(I%)>10.2 THEN HIT(I%)=99.999 1290 NEXT 1% 1300 SH1#=0 : SH2#=0 : SR1#=0 : SR2#=0 1310 FOR I%=1 TO NHITS% SH1#=SH1#+LUMIN(NSH0T%,I%) : SH2#=SH2#+LUMIN(NSH0T%,I%)*LUMIN(NSH0T%,I%) : SR1#=SR1#+REFER(NSH0T%,I%) : SR2#=SR2#+REFER(NSH0T%,I%)*REFER(NSH0T%,1%) : NEXT 1% 1320 MEAN#=SH1#/NHITS% : REFMEAN#=SR1#/NHITS% : STDDEV#=SQR(ABS((SH2#-SH1#*SH1#/NHITS%)/(NHITS%-1))) : REFSD#=SQR(ABS((SR2#-SR1#*SR1#/NHITS%)/(NHITS%-1))) 1330 SH0T(NSH0T%,0)=MEAN# : SHOT(NSH0T%,1)=STDDEV# 1340 PRINT USING"####";LAMDA%; : PRINT"A"; : PRINT USING"###.###";NSH0T%*DELAYSCALE*DV0LTS; : PRINT"us SIG="; : PRINT USING"##.####";SH0T(NSH0T%,0); : PRINT", sd="; : PRINT USING"##.####";SH0T(NSH0T%,1); 1342 PRINT","; : PRINT USING "###.#";ABS(100*SH0T(NSH0T%,1)/SH0T(NSH0T%,0)); : PRINT "%, REF="; : PRINT USING"##.###";REFMEAN#; : PRINT " sd="; : PRINT USING"###.#";100*REFSD#/REFMEAN#; : PRINT'T' 1350 NEXT NSH0T% 170 1360 0PEN"A",2,FILENAME$ 1370 FOR I%-1 TO NWINDOWS% 1371 FOR J%=1 TO NHITS% 1372 PRINT#2,USING" ##.###";LUMIN(I%,J%); 1373 NEXT J% 1374 PRINT#2," " 1375 FOR J%=1 TO NHITS% 1376 PRINT#2,USING" ##.###";REFER(I%,J%); 1377 NEXT J% 1378 PRINT#2," " 1379 NEXT 1% 1380 CLOSE 2 1390 NEXT LAMDA% 1400 'SET MONOCHROMATOR BACK TO START POSITION 1500 PRINT BELL$;"RUN FOR ";FILENAME$;" COMPLETED AT ";TIME$;" ON ";DATE$ 9999 GOTO 32767 10100 'MONOCHROMATOR DRIVER SUBROUTINE USE MOTHERBOARD PARALLEL PRINTER PORT SET MONOCHROMATOR CONTROLLER TO 20 ANGSTROMS/SEC THERE ARE 60 PULSES PER ANGSTROM DO NOT EXCEED 600 HZ PULSING!! (20 A/SEC IS MAXIMUM SPEED) 10102 * PARALLEL PORT PIN ASSIGNMENTS: PIN VALUE FUNCTION 10104 ' 2 1 TOGGLE FOR STEPPER MOTOR PULSING 7 32 HIGH = CLOSES RELAY TO CONNECT MONOCHROMATOR 7 32 LOW = OPENS RELAY TO DISCONNECT MONOCHROMATOR 10110 PF=60 : SLMAX=60000! : KAH%=234 : KAL%=96 10120 SLEW =ABS(PF*(ANGEND%-ANGSTART%)) : IF SLEW <4 THEN RETURN 10125 OUT &H3BC&H20 'TURNS MONOCHROMATOR RELAY ON 10130 PRINT"SLEWING ";SLEW/PF;" ANGSTROMS NOW - BE PATIENT" 10135 SLEW=SLEW-2 'DUE TO EXTRA TOGGLES CREATED BY ISOLATION RELAY!!! 10140 IF SLEW<=SLMAX THEN 10190 10150 SLEW=SLEW-SLMAX 10160 POKE &HFFF0,KAL% : POKE &HFFF1,KAH% : I=USRO(0) 10170 IF SLEW=0 THEN 10198 10180 GOTO 10140 10190 AH%=INT(SLEW/256) : AL%=INT(SLEW-256*AH%) : POKE &HFFF0,AL% : POKE &HFFF1,AH% : I=USRO(0) 10198 OUT &H3BC.&H0 'TURNS MONOCHROMATOR RELAY OFF 10199 RETURN 171 10200 'SERIAL COMMUNICATIONS SETUP SETS P0RT#1 FOR 9600 BAUD, NO PARITY, 8DATA BITS, 2 STOP BITS 10210 0PEN"C0M1:9600,N,8,2,CS,DS,CD" AS #1 : PRINT#1," " : PRINT#1,"MR;W25" 10299 RETURN 10300 'SETUP BOXCAR INTERFACE PORTS • 10310 PRINT#1,"I5" 'PORTS 1-5 INPUT; PORTS 6-8 OUTPUT 10320 PRINT#1,"S8=0" 10399 RETURN 10500 'LIST SHOT BY SHOT DATA ON SCREEN 10510 FOR KK%=1 TO NHITS% PRINT USING" ##.###";LUMIN(NSH0T%,KK%); NEXT KK% PRINT 10520 FOR KK%=1 TO NHITS% : PRINT USING" ##.###";REFER(NSH0T%,KK%); : NEXT KK% : PRINT 10599 RETURN • 10800 'FIRE LASER VIA P0RT#7, TAKE LUMINESCENCE & REFERENCE PMT VALUES 10820 PRINT#1,"S6=5" 10825 PRINT#1,"S7=10" 10830 PRINT#1,"S7=0" 10840 GOSUB 30800 10870 PRINT#1,"?2" : INPUT*1,REF$ : PRINT#1,"S6=0" : PRINT#1,"?1" : INPUT#1,LUM$ 10899 RETURN 18100 'APPARATUS CABLE CONNECTIONS: 18110 'BOXCAR AVERAGER MODULE: 18120 'BOXCAR INPUTS: TRIGGER - PHOTODIODE TRIGGER UNIT : SIGNAL - SIGNAL PHOTOMULTIPLIER 18130 'COMPUTER INTERFACE MODULE: 18140 'CHANNEL #1 - BOXCAR LAST SAMPLE OUTPUT : #2 - PEAK DETECTOR UNIT OUTPUT : #6 - PEAK DETECTOR UNIT RESET : #7 - LASER EXTERNAL TRIGGER 172 : #8 - BOXCAR EXTERNAL DELAY (ON BOXCAR REAR PANEL) 18150 'PEAK DETECTOR MOULE: 18160 'INPUT - REFERENCE PMT : OUTPUT - INTERFACE CHANNEL #2 : RESET - INTERFACE CHANNEL #6 18170 'CORONA COMPUTER: 18180 'PARALLEL PORT - MONOCHROMATOR ISOLATION RELAY : SERIAL PORT - SRS COMPUTER INTERFACE 18300 'NORMAL SWITCH SETTINGS: • 18310 'MONOCHROMATOR SCANNER: 18320 'FRONT PANEL: : SCAN DIRECTION : SCAN RATE : SCAN : SLEW : REAR PANEL: : EXT. INPUT 18330 'BOXCAR MODULE: • 18340 'TRIGGER RATE - EXT. : THRESHOLD - VARY : DELAY SCALE - VARY : MULTIPLIER - ZERO : WIDTH SCALE - VARY : MULTIPLIER - NORMALLY AT 1 18345 'SIGNAL SENSITIVITY - VARY : INPUT FILTER - DC : INPUT OFFSET - VARY : AVERAGING - LAST SAMPLE i8348 'REAR PANEL SWITCHES: : LAST SAMPLE - INVERTED : AVERAGE - INVERTED 30800 'DELAY ROUTINE 30810 FOR F00P=1 TO 10 : FOOQ=FOOQ : NEXT FOOP 30899 RETURN • 32767 END - INCREASE - 20 ANGSTROMS/SEC - CONTINUOUS - OFF (BOTH SWITCHES) - EXT. 173 APPENDIX 2 MONOCHROMATOR STEPPER MOTOR DRIVER ROUTINE FFOO B80000 MOV AX,0000 ; Set AX register to zero FF03 A3F2FF MOV [FFF2],AX ; Set $FFF2 to value in AX FF06 FF06F2FF INC WORD PTR [FFF2] ; Add 1 to value in $FFF2 ; Toggle the stepper motor line high FFOA BABC03 MOV DX,03BC ; Set DX register to $03BC FFOD B07F MOV AL.7F ; Parallel port pin #2 high FFOF EE OUT DX,AL Output AL to port DX ; Wait routine -• so we don't toggle the poor stepper motor too fast FF10 B80000 MOV AX,0000 ; Set AX register to zero FF13 A3F6FF MOV [FFF6],AX ; Set $FFF6 to value in AX FF16 FF06F6FF INC WORD PTR [FFF6] Add 1 to value in $FFF6 FF1A BEF4FF MOV SI.FFF4 Set SI to value in $FFF4 FF1D BFF6FF MOV DI,FFF6 Set DI to value in $FFF6 FF20 A7 CMPSW SI minus DI, is i t zero? FF21 75F3 JNZ FF16 Jump to $FF16 i f not done ; Now we toggle stepper motor line low FF23 BABC03 MOV DX,03BC ; Set DX register to $03BC FF26 B07E MOV AL.7E ; Parallel port pin #2 low FF28 EE OUT DX.AL Output AL to port DX ; Another pause for the belabored stepper motor FF29 B8000 MOV AX,0000 ; Set AX register to zero FF2C A3F6FF MOV [FFF6],AX ; Set $FFF6 to value in AX FF2F FF06F6FF INC WORD PTR [FFF6] ; Add 1 to value in $FFF6 FF33 BEF4FF MOV SI.FFF4 ; Set SI to value in $FFF4 FF36 BFF6FF MOV DI,FFF6 ; Set DI to value in $FFF6 FF39 A7 CMPSW ; SI minus DI, is i t zero? FF3A 75F3 JNZ FF2F ; Jump to $FF2F i f not done ; Have we slewed the desired distance? FF3C BEFOFF MOV SI.FFFO ; Set SI to value in $FFF0 FF3F BFF2FF MOV DI.FFF2 ; Set DI to value in $FFF2 FF42 A7 CMPSW ; SI minus DI, is i t zero? FF43 75C1 JNZ FF06 ; Jump to $FF06 i f not done FF45 CB RETF ; Return to BASIC program 1 7 4 APPENDIX 3 LUMINESCENCE DATA FILE HANDLER IN BASIC 1 'PROGRAM SQUEEZEM - REVISION 2.3 - 871128 - BASIC 2 'BY E. F. PASKI * (C) COPYRIGHT 1987 * ALL RIGHTS RESERVED 3 'CONVERTS RAW DATA FILES FROM SPECTROMETER ACQUISITION PROGRAM: - COMPRESSES DATA FILES BY AVERAGING SHOT BY SHOT VALUES - APPLIES SYSTEM SPECTRAL RESPONSE CORRECTION - CREATES ENERGRAPHICS FORMAT DATA FILES FOR 3D GRAPHICS 4 10 PRINT"PROGRAM SQUEEZEM - REV 2.3 - 871128" : PRINT 12 PRINT"CONVERTS '.LCD' FILES TO '.SCC FILES: SPECTRAL CORRECTION USING'' 14 PRINT"CARBON TETRACHLORIDE FILTER" : PRINT:PRINT 16 'FOR METHANOL FILTER CORRECTION USE LINES 8000-8999 IN PLACE OF 7000-7999 100 OPTION BASE 1 110 'MAIN DATA ARRAY X(Q,TIME,WAVELENGTH) : Q=l - SPECTRAL RESPONSE CORRECTED SPECTRUM : Q=2 - STANDARD DEVIATION FOR Q=l : Q=3 - BACKGROUND & DROOP ONLY CORRECTED SPECTRUM : Q=4 - DROOP CORRECTION FACTOR 118 DIM XI(20),RI(20),LUM(20),REF(20) 120 DIM X(4,31,51),C(551),ABAK(31),BBAK(31),DB$(13),DA$(13),EA$(8) 130 ZER0=1E-10 200 'INPUT DATA FILE NAMES & READ 210 GOSUB 1000 400 GOSUB 5000 610 GOSUB 6000 990 PRINT "FINISHED AT ";TIME$ 999 GOTO 32767 1000 ' 1001 INPUT"FIRST BACKGROUND FILE NAME";A$ : ABAKFIL$=A$ 1010 IF INSTR(A$,".")=0 THEN ABAKFIL$=LEFT$(A$,8)+".LCD" 1015 0PEN"I",1,ABAKFIL$ : PRINT"FILE ";ABAKFIL$;" PRESENT" : CLOSE 1 1020 INPUT"SECOND BACKGROUND FILE NAME";A$ : BBAKFIL$=A$ 1030 IF INSTR(A$,".")=0 THEN BBAKFIL$=LEFT$(A$,8)+".LCD" 1035 0PEN"I",1,BBAKFIL$ : PRINT"FILE ";BBAKFIL$;" PRESENT" : CLOSE 1 1040 INPUT"SPECTRA DATA FILENAME";A$ : DATAFILE$=A$ 1050 IF INSTR(A$,".")=0 THEN DATAFILE$=LEFT$(A$,8)+".LCD" 1055 0PEN"I",1,DATAFILE$ : PRINT"FILE ";DATAFILE$;" PRESENT" : CLOSE 1 1060 GOSUB 7000 'SPECTRAL RESPONSE DATA 1090 PRINT"READING BACKGROUND NOISE FILES" 1100 0PEN"I",1,ABAKFIL$ : 0PEN"I",2,BBAKFIL$ 1110 FOR I%=1 TO 13 : INPUT #1,DA$(I%) : INPUT #2,DB$(I%) : NEXT 1% 1120 NM$="A" : GOSUB 3000 : IF NM$="X" THEN PRINT"FILE A = ";ABAKFIL$;", FILE B - ";BBAKFIL$ : GOTO 2000 175 1130 STWL%=VAL(DA$(10)) : ENWL%=VAL(DA$(11)) : INWL%=VAL(DA$(12)) : NTIMES%=VAL(DA$(9)) : NHITS%=VAL(DA$(8)) 1140 NWAVES%=1+(ENWL%-STWL%)/INWL% 1190 REFBAK=0 : RB%=0 1200 FOR W%=1 TO NWAVES% 1210 FOR T%=1 TO NTIMES% 1220 ABK=0 : BBK=0 1230 FOR I%=1 TO NHITS% : INPUT#1,X : ABK=ABK+X : NEXT 1% 1240 FOR I%=1 TO NHITS% : INPUT#1,R : REFBAK=REFBAK+R : RB%=RB%+1 : NEXT 1% 1250 FOR I%=1 TO NHITS% : INPUT#2,X : BBK=BBK+X : NEXT 1% 1260 FOR I%=1 TO NHITS% : INPUT#2,R : REFBAK=REFBAK+R : RB%=RB%+1 : NEXT 1% 1270 ABAK(T%)=ABAK(T%)+ABK/NHITS% : BBAK(T%)=BBAK(T%)+BBK/NHITS% 1280 NEXT T% 1290 NEXT W% 1300 FOR I%=1 TO NTIMES% : ABAK(I%)=ABAK(I%)/NWAVES% : BBAK(I%)=BBAK(I%)/NWAVES% : NEXT 1% 1310 REFBAK=REFBAK/RB% 1320 CLOSE 1,2 2000 'READ MAIN DATA FILE, DO BACKGROUND SUBTRACTION, DISCARD OUTLIERS 2025 PRINT"READING DATA FILE - TIME IS ";TIME$ 2030 OPEN"I",1,DATAFILE$ 2040 FOR I%=1 TO 13 : INPUT*1,DA$(I%) : NEXT 1% 2050 GOSUB 3000 : IF NM$="X" THEN PRINT"FILE A = ";DATAFILE$;", FILE B = ";BBAKFIL$ : PRINT"PROGRAM ABORTED" : GOTO 32767 2060 STWL%=VAL(DA$(10)) : ENWL%=VAL(DA$(11)) : INWL%=VAL(DA$(12)) : NTIMES%=VAL(DA$(9)) 176 : NHITS%=VAL(DA$(8)) : NWAVES%=1+(ENWL%-STWL%)/INWL% : DV0LTS=VAL(DA$(7)) : DELAYSCALE=VAL(DA$(6)) 2200 'SUBTRACT BACKGROUND 2220 FOR W%=1 TO NWAVES% 2230 FOR T%=1 TO NTIMES% 2240 X1=0 : X2=0 : R1=0 : BN= ABAK(T%)-(ABAK(T%)-BBAK(T%))*((W%-1)/(NWAVES%-1)) 2260 FOR I%=1 TO NHITS% : INPUT#1,LUM(I%) : NEXT 1% : FOR I%=1 TO NHITS% : INPUT#1,REF(I%) : NEXT 1% : J%=0 : X1=0 : X2=0 2270 FOR I%=1 TO NHITS% : IF REF(I%)>10.236 THEN 2300 2280 REF(1%)=REF(1%)-REFBAK : IF REF(I%)>RMAX THEN RMAX=REF(I%) 2285 IF REF(I%)<.4999 THEN 2300 2290 LUM(I%)=LUM(I%)-BN : J%=J%+1 : XI(J%)=LUM(I%) : RI(J%)=REF(I%) : X1=X1+XI(J%) : X2=X2+XI(J%)*XI(J%) : R1=R1+RI(J%) 2300 NEXT 1% 2302 IF J%=0 THEN K%=1 : X1=ZER0 : R1=ZER0 : SDX=X1 : GOTO 2350 2304 IF J%=1 THEN K%=1 : SDX=X1 : GOTO 2350 2310 MN=X1/J% : SD2=SQR((X2-X1*X1/J%)/(J%-1)) : TV=MN-SD2 : X1=0 : R1=0 : K%=0 : X2=0 2320 FOR I%=1 TO J% : IF XI(I%)<TV THEN 2340 2330 K%=K%+1 : T=XI(I%)/RI(I%) : X1=X1+T : X2=X2+T*T : R1=R1+RI(I%) 2340 NEXT 1% 2345 SDX=SQR((X2-X1*X1/K%)/(K%-1)) 2350 REM 2352 X(2,T%,W%)=SDX 2353 X(3,T%,W%)=X1/K% 2354 X(4,T%,W%)=R1/K% 2360 NEXT T% 2370 NEXT W% 2380 CLOSE 1 2390 PRINT"FINISHED READING DATA FILES" 2600 FOR W%=1 TO NWAVES% 2605 L%=((STWL%+(W%-l)*INWL%)-2490)/10 2606 IF L%<1 THEN L%=1 2607 IF L%>551 THEN L%=551 177 2608 SCF=1/C(L%) 2610 FOR T%=1 TO NTIMES% 2620 X(4,T%,W%)=X(4,T%,W%)/RMAX 'NORMALIZE DROOP FACTOR 2622 X(3,T%,W%)=X(3,T%,W%)*RMAX 2624 X(2,T%,W%)=X(2,T%,W%)*RMAX*SCF 'STD. DEV. CORRECTION 2626 X(1,T%,W%)=X(3,T%,W%)*SCF 'LUMINESCENCE SPECTRAL CORRECTION 2730 NEXT T% 2740 NEXT W% 2999 RETURN 3000 'CHECK FOR MISMATCHED FILE PARAMETERS 3100 IF DA$(6)ODB$(6) THEN NM$="X" : PRINT"DELAY SCALES DON'T MATCH - FILE A =";DA$(6);" FILE B =";DB$(6) 3110 IF DA$(7)ODB$(7) THEN NM$="X" : PRINT"DELAY STEPS DON'T MATCH - FILE A =";DA$(7);" FILE B =";DB$(7) 3120 IF DA$(8)ODB$(8) THEN NM$="X" : PRINT"# HITS DON'T MATCH - FILE A =";DA$(8);" FILE B =";DB$(8) 3130 IF DA$(9)ODB$(9) THEN NM$="X" : PRINT"# WINDOWS DON'T MATCH - FILE A =";DA$(9);" FILE B =";DB$(9) 3140 IF DA$(13)ODB$(13) THEN NM$="X" : PRINT"WINDOW WIDTHS DON'T MATCH - FILE A =";DA$(13);" FILE B =";DB$(13) 3999 RETURN 5000 'SAVE BACKGROUND CORRECTED DATA 5010 BAKCORFIL$=LEFT$(DATAFILE$,INSTR(DATAFILE$,"."))+"SCC" 5020 DA$(2)="$ "+DA$(2) 'FLAG FOR CORRECTED DATA 5030 GE$="###.#### ###.#### ###.#### ###.####" 5100 PRINT : PRINT"SAVING CORRECTED DATA UNDER FILE NAME ";BAKC0RFIL$ 5110 0PEN"0",#1,BAKC0RFIL$ 5120 PRINT#1, BAKC0RFIL$ : FOR I%=2 TO 13 : PRINT#1, DA$(I%) : NEXT 1% 5130 FOR M%=1 TO NWAVES% 5140 FOR N%=1 TO NTIMES% 5160 PRINT#1,USING GE$; X(l,N%,M%),X(2,N%,M%),X(3,N%,M%),X(4,N%,M%) 5170 NEXT N% 5180 NEXT M% 5190 CLOSE 1 5200 PRINT CHR$(7) 5999 RETURN 6000 ' 6001 ENERFILE$=LEFT$(DATAFILE$,INSTR(DATAFILE$,"."))+"SUR" 6010 IF INSTR(ENERFILE$,".")=0 THEN ENERFILE$=LEFT$(ENERFILE$,8)+".SUR" 6012 IF INSTR(ENERFILE$,".SUR")=0 THEN ENERFILE$=LEFT$(ENERFILE$,8)+".SUR" 6030 XA$=" Time, us" 6040 YA$=" Wavelength, nm" 6050 ZA$="Relative Intensity" 6100 'SET UP ENERGRAPHICS FILE HEADER 6105 SPASE$=" " 6110 EA$(1)=RIGHT$(SPASE$+DA$(2),50) 6112 TEM$=LEFT$(ENERFILE$,LEN(ENERFILE$)-4) 6114 EA$(1)=TEM$+MID$(EA$(1),LEN(TEM$)) 6120 EA$(2)=DA$(5)+" at "+DA$(4) 6130 A=DELAYSCALE*DVOLTS 6132 EA$(3)=MID$(STR$(A)+SPASE$,2,5)+XA$+RIGHT$(SPASE$+STR$(A*NTIMES%),5) 178 6140 A=10 6142 EA$(4)=MID$(STR$(.1*STWL%)+SPASE$,2,A)+YA$+RIGHT$(SPASE$+STR$(.1*ENWL%),A) 6143 EA$(4)=MID$(STR$(.1*STWL%)+SPASE$,2,8)+YA$+RIGHT$(SPASE$+STR$(.1*ENWL%),9) 6150 EA$(5)=ZA$ 6160 EA$(6)=STR$(NTIMES%)+","+STR$(NWAVES%)+",l,*'+STR$(NTIMES%)+","+STR$(STWL%) +","+STR$(ENWL%) 6162 EA$(6)=STR$(NTIMES%)+","+STR$(NWAVES%)+",1,20,3000,5000" 6170 Al$=".2," : IF NTIMES%=20 THEN Al$=".25," 6172 A2$=".0016,.5,-200,40" 6173 IF(STWL%=3500 AND ENWL%=7000) THEN A2$=".002,.5,-350,30" 6174 IF(STWL%=2500 AND ENWL%<=5000) THEN A2$=".0029,.5,-200,25" 6175 IF(STWL%=2500 AND ENWL%=6000) THEN A2$=".002,.5,-225,50" 6176 IF(STWL%=3000 AND ENWL%=5000) THEN A2$=".0032,.5,-475,5" 6179 EA$(7)=A1$+A2$ 6180 EA$(8)="60,30,3,0" 6182 EA$(7)=".25,.0032,.2,-475,5" 6200 0PEN"0",#1,ENERFILE$ 6205 PRINT : PRINT"WRITING FILE ";ENERFILE$;" TO DISC 6210 FOR I%=1 TO 8 6220 PRINT#1,EA$(I%) 6230 NEXT 1% 6240 FOR I%=1 TO NTIMES% 6250 FOR J%=1 TO NWAVES% 6260 PRINT#1, X(1,I%;J%) 6270 NEXT J% 6280 NEXT 1% 6290 CLOSE 1 6999 RETURN 7000 'DATA FOR CARBON TETRACHLORIDE FILTER - SMOOTHED WITH A 3 POINT MOVING AVERAGE 7010 FOR I%=1 TO 551 : READ C(I%) : NEXT 1% 7201 DATA .00010, .01878, .02200, .01676, .01235, .03393, .03342, .03342, .00862, .00010 7202 DATA .01823, .01823, .04728, .06868, .09121, .08180, .07153, .08246, .09337, .10475 7203 DATA .10527, .12337, .10932, .10472, .08795, .10595, .11150, .12162, .13138, .14454 7204 DATA .14750, .14164, .15112, .14597, .13956, .13999, .14886, .16519, .16187, .16915 7205 DATA .16728, .17482, .17263, .17539, .17205, .18156, .19474, .20036, .20388, .20377 7206 DATA .21191, .21917, .22964, .22972, .23514, .23258, .23985, .24069, .24607, .25469 7207 DATA .26626, .27006, .27907, .27886, .28641, .28607, .28870, .29315, .29725, .30665 7208 DATA .30673, .30722, .30910, .31220, .31204, .31635, .31891, .33003, .33040, .33439 7209 DATA .33846, .34510, .34677, .34380, .34217, .34314, .34868, .35234, .35777, .36154 7210 DATA .36553, .36900, .37062, .37474, .38123, .38658, .39173, .39817, .40610, .41332 7211 DATA .42197, .42900, .43703, .44276, .45153, .45932, .46703, .47405, .47953, .48844 7212 DATA .49984, .51490, .52273, .53001, .53463, .54407, .55414, .57068, .58236, .58819 7213 DATA .59570, .60469, .61881, .63202, .64532, .65649, .65863, .66477, .67422, .69462 7214 DATA .71418, .72945, .73463, .74161, .75038, .76495, .77567, .78652, .79313, .80356 7215 DATA .81325, .83132, .84257, .85408, .85734, .86645, .87627, .88655, .89286, .89959 7216 DATA .89229, .88964, .88544, .89677, .90540, .90594, .90467, .90839, .91429, .92527 7217 DATA .92680, .92890, .92602, .92824, .93344, .93994, .94586, .95078, .95263, .95468 7218 DATA .95924, .96432, .97047, .97414, .97767, .97674, .97970, .98254, .98684, .99161 7219 DATA .99465, .99450, .99353, .99101, .99281, .98909, .98662, .98122, .97899, .97743 7220 DATA .97522, .97002, .96175, .95532, .94898, .94629, .94178, .93649, .92770, .91878 7221 DATA .91107, .90543, .89975, .89413, .88640, .88064, .87401, .86838, .86484, .86012 7222 DATA .85848, .85254, .85214, .84834, .84667, .84230, .83975, .83590, .83079, .82722 179 7223 DATA .82230, .81777, .81255, .80763, .80180, .79588, .79084, .78542, .78011, .77476 7224 DATA .77120, .76651, .76225, .75635, .75150, .74444, .73930, .73335, .72915, .72391 7225 DATA .71855, .71415, .70919, .70448, .69936, .69497, .69002, .68463, .67980, .67543 7226 DATA .67114, •6661L, .66097, .65629, .65166, .64800, .64418, .64004, .63424, .62910 7227 DATA .62424, .62038, .61588, .61228, .60831, .60452, .60087, .59708, .59347, .58878 7228 DATA .58507, .58059, .57681, .57295, .56924, .56553, .56142, .55798, .55473, .55108 7229 DATA .54740, .54374, .54028, .53636, .53299, .52953, .52645, .52265, .52027, .51747 7230 DATA .51483, .51095, .50693, .50312, .49984, .49650, .49366, .49070, .48867, .48515 7231 DATA .48244, .47968, .47740, .47448, .47101, .46789, .46518, .46250, .46038, .45721 7232 DATA .45419, .45105, .44860, .44693, .44417, .44127, .43779, .43570, .43377, .43102 7233 DATA .42845, .42563, .42372, .42120, .41909, .41656, .41422, .41167, .40951, .40801 7234 DATA .40613, .40416, .40165, .39941, .39727, .39516, .39267, .39058, .38858, .38684 7235 DATA .38510, .38275, .38101, .37919, .37708, .37529, .37294, .37106, .36907, .36788 7236 DATA .36657, .36479, .36247, .36038, .35816, .35658, .35449, .35308, .35096, .34937 7237 DATA .34783, .34628, .34462, .34256, .34070, .33916, .33764, .33605, .33435, .33262 7238 DATA .33073, .32879, .32727, .32564, .32425, .32209, .32099, .31939, .31805, .31603 7239 DATA .31441, .31231, .31060, .30871, .30751, .30596, .30390, .30208, .30054, .29966 7240 DATA .29824, .29640, .29447, .29279, .29123, .28985, .28823, .28667, .28528, .28352 7241 DATA .28214, .28018, .27850, .27665, .27553, .27475, .27366, .27198, .27050, .26904 7242 DATA .26738, .26567, .26413, .26249, .26078, -25931, .25804, .25645, .25456, .25312 7243 DATA .25154, .25007, .24835, .24690, .24550, .24364, .24262, .24050, .23915, .23728 7244 DATA .23594, .23388, .23203, .23034, .22905, .22754, .22630, .22494, .22297, .22118 7245 DATA .21954, .21789, .21646, .21519, .21368, .21175, .20982, .20803, .20612, .20442 7246 DATA .20261, .20155, .19923, .19742, .19531, .19432, .19381, .19298, .19257, .19240 7247 DATA .19211, .19092, .18904, .18807, .18690, .18613, .18479, .18347, .18181, .18006 7248 DATA .17818, .17669, .17454, .17339 .17102, .16956, .16718, .16547, .16320, .16065 7249 DATA .15804, .15514, .15350, .15155, .14976, .14751, .14446, .14219, .13910, .13755 7250 DATA .13546, .13314, .13058 .12824, .12652, .12494, .12292, .12084 .11785, .11618 7251 DATA .11450, .11331, .11110, .10928, .10802, .10664, .10495, .10279, .10075, .09888 7252 DATA .09715, .09571, .09481, .09382 .09281, .09136 .09009 .08895 .08785 .08621 7253 DATA .08521, .08375, .08325, .08186, .08086, .07964, .07873, .07808, .07708, .07594 7254 DATA .07482, .07396, .07298, .07212, .07109, .07029, .06952, .06883, .06811, .06745 7255 DATA .06674, .06576, .06470, .06416, .06400, .06368, .06290, .06230, .06123, .06060 ,.05992 7999 RETURN 'r : 8000 'DATA FOR METHANOL FILTER - SMOOTHED WITH A 3 POINT MOVING AVERAGE 8010 FOR I%=1 TO 551 : READ C(I%) : NEXT IZ 69409,.66074,.62706,.59737,.58709,.60040 8101 DATA .75168 8102 DATA .52574 8103 DATA .41005 8104 DATA .33769 8105 DATA .31673 8106 DATA .33170 8107 DATA .35716 8108 DATA .36318 8109 DATA .38609 8110 DATA .36133 8111 DATA .39941 8112 DATA .47185 8113 DATA .55187 8114 DATA .68409 8115 DATA .81001 8116 DATA .85915 8117 DATA .90235 .53244,.49083 .42855,.42507 .34556,.35390 .31745,.32528 .32011,.32719 .35937,.36073 .36702,.36946 .38482,.38081 .37082,.37946 .40052,.39791 .49656,.51358 .55446,.55318 .70557,.72117 .82513,.83697 .86362,.86830 .90457,.90220 .48193,.46513,.43307,.45309 .39957,.37681,.36086,.36434 .35213,.32819,.31858,.32291 .33141,.32661,.32637,.32837 .32312,.32922,.33231,.34371 .37281,.37868,.38230,.37445 .37104,.36867,.36840,.37479 .37153,.36162,.36055,.35561 .38986,.39631,.39919,.40262 .39942,.39642,.39517,.39488 .53102,.54275...55004,.55757 .54484,.53028,.52445,.53754 .73411,.74811,.76401,.77413 .84580,.84481,.84607,.84868 .87549,.88013,.88510,.88636 .90538,.90802,.91510,.92173 .59013,.54360 .45379,.44462 .37313,.37368 .33035,.33285 .32814,.33062 .35554,.35798 .37457,.36741 .37728,.38408 .35703,.35530 .40587,.40822 .40118,.41814 .55915,.55827 .57059,.61292 .78282,.78946 .85449,.85776 .88977,.89282 .92820,.93109 .55848 .41383 .36028 .32468 .32770 .35960 .36728 .37915 .35921 .40662 .44637 .55301 .65225 .79923 .85883 .90082 .93375 180 8118 DATA .93614, .94030, .94437, .94823, .95143, .95201, .95662, .96045, .96596, .97267 8119 DATA .98029, .98813, .99146, .99465, .99565, .99277, .98909, .98672, .98825, .98850 8120 DATA .99104, .98919, .98717, .98104, .97836, .97337, .96867, .96283, .95932, .95491 8121 DATA .94964, .94414, .93929, .93348, .92922, .92634, .92577, .92867, .93129, .93361 8122 DATA .93251, .93481, .94151, .94775, .95534, .96077, .96643, .96962, .97350, .97980 8123 DATA .98297, .98477, .98318, .98523, .98849, .99378, .99600, .99590, .99636, .99674 8124 DATA .99744, .99614, .99566, .99579, .99540, .99542, .99536, .99511, .99379, .99290 8125 DATA .99231, .99031, .98755, .98462, .98288, .98222, .97948, .97842, .97460, .97331 8126 DATA .96973, .96898, .96597, .96335, .95880, .95569, .95399, .95179, .94905, .94545 8127 DATA .94182, .93951, .93587, .93328, .93055, .92776, .92551, .92230, .91951, .91407 8128 DATA .91102, .90737, .90553, .90208, .89855, .89388, .88962, .88593, .88336, .87968 8129 DATA .87593, .87160, .86794, .86471, .86067, .85529, .85090, .84776, .84455, .84012 8130 DATA .83579, .83062, .82725, .82236, .82043, .81601, .81209, .80780, .80356, .79949 8131 DATA .79370, .78950, .78514, .78242, .77782, .77416, .76864, .76557, .76164, .75860 8132 DATA .75377, .74910, .74358, .73843, .73465, .73088, .72737, .72250, .71811, .71403 8133 DATA .71135, .70724, .70256, .69806, .69443, .69119, .68627, .68187, .67703, .67184 8134 DATA .66717, .66326, .65981, .65639, .65279, .64936, .64586, .64221, .63939, .63569 8135 DATA .63131, .62680, .62316, .61943, .61591, .61119, .60811, .60413, .60122, .59656 8136 DATA .59272, .58883, .58662, .58311, .57965, .57583, .57223, .56822, .56354, .55959 8137 DATA .55521, .55065, .54648, .54225, .53860, .53481, .53053, .52661, .52175, .51735 8138 DATA .51245, .50742, .50386, .49943, .49532, .48996, .48599, .48144, .47672, .47084 8139 DATA .46720, .46290, .45933, .45432, .45032, .44540, .44073, .43608, .43261, .42782 8140 DATA .42393, .41847, .41435, .40957, .40604, .40207, .39818, .39335, .38893, .38445 8141 DATA .38112, .37703, .37268, .36762, .36323, .35979, .35636, .35281, .34878, .34438 8142 DATA .34070, .33637, .33315, .32899, .32475, .32038, .31714, .31410, .31105, .30674 8143 DATA .30256, .29839, .29489, .29142, .28803, .28415, .28124, .27771, .27467, .27093 8144 DATA .26793, .26448, .26118, .25747, .25464, .25149, .24886, .24536, .24231, .23959 8145 DATA .23694, .23422, .23068, .22754, .22445, .22136, .21864, .21578, .21347, .21088 8146 DATA .20885, .20664, .20412, .20103, .19859, .19617, .19527, .19454, .19506, .19489 8147 DATA .19480, .19364, .19246, .19086, .18992, .18870, .18720, .18510, .18308, .18125 8148 DATA .17959, .17731, .17463, .17235, .17009, .16815, .16588, .16375, .16115, .15863 8149 DATA .15578, .15307, .15041, .14815, .14622, .14406, .14138, .13854, .13585, .13385 8150 DATA .13169, .12930, .12728, .12514, .12331, .12099, .11915, .11709, .11525, .11319 8151 DATA .11144, .10974, .10825, .10661, .10502, .10363, .10258, .10162, .10048, .09881 8152 DATA .09733, .09614, .09539, .09430, .09315, .09199, .09076, .08976, .08851, .08757 8153 DATA .08630, .08531, .08430, .08342, .08259, .08183, .08097, .08010, .07905, .07811 8154 DATA .07722, .07634, .07526, .07444, .07353, .07284, .07211, .07146, .07073, .06977 8155 DATA .06908, .06832, .06757, .06671, .06603, .06559, .06482, .06415, .06338, .06291 ,.06236 8999 RETURN 32767 PRINT : PRINT"BYE!" : CLOSE : END 181 A P P E N D I X 4 DATA REDUCTION PROGRAM U S I N G S I M P L E X O P T I M I Z A T I O N C C PROGRAM ZECONC.FOR C C DATA REDUCTION FOR MULTIDIMENSIONAL LUMINESCENCE SPECTRA - FORTRAN 77 C C COPYRIGHT 1988 BY E. F. PASKI - ALL RIGHTS RESERVED C C REVISION 3.15 - 880303 - General version - uses four column input f i l e C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N, WLST,WLEN,TMST,TMEN,DLY.WHW,NCOMP,PMV C C C C C C C C C C C C C C C C C C C C C C c c c c c c c c c c c *** COMMON VARIABLES (NON DIMENSIONED): NWAVES = NUMBER OF WAVELENGTH CHANNELS NTIMES = NUMBER OF TIME CHANNELS N = NUMBER OF UNKNOWN SPECIES TO FIND WLST = STARTING WAVELENGTH, ANGSTROMS WLEN = END WAVELENGTH, ANGSTROMS TMST = STARTING TIME, MICROSECONDS TMEN = END TIME, MICROSECONDS DLY = DELAY TIME INTERVAL, MICROSECONDS WHW = GATE TIME WINDOW, HALF WIDTH NCOMP = NUMBER OF UNKNOWN SPECIES TO PMV = NUMBER OF PARAMETERS TO VARY FIND IN SIMPLEX OPTIMIZATION DIMENSIONED VARIABLES: WHERE: T = NUMBER OF TIME CHANNELS, DEFAULT TO 30 W = NUMBER OF WAVELENGTH CHANNELS, DEFAULT TO 51 U = NUMBER OF COMPONENTS, DEFAULT TO 5 CNTRD(5*U) CP(U,T) CPT(T,U) CTAU(5*U) D(T,W) DA(15) DP(T.W) MXI(5*U,5*U) MXIPV(5*U,3) NU(W) P(5*U+5,4*U+1) PMX(5) CENTROID IN SIMPLEX TIME BEHAVIOUR MATRIX TRANSPOSE OF [CP] SIMPLEX FOR TIMES ORIGINAL DATA MATRIX SPECTRUM REGION DATA MATRIX COMPUTED DATA MATRIX MATRIX TO BE INVERTED PIVOT FOR MATRIX INVERSION RECIPROCAL ANGSTROMS PARAMETER MATRIX FOR SIMPLEX OPTIMIZATION POINTER MATRIX FOR SELECTING COMPONENTS TO VARY 182 C SAP(W.U) = WAVELENGTH BEHAVIOUR MATRIX C SURPRM(U,5) = SURFACE PARAMTER MATRIX C TP(5*U+1) = TEMPORARY STORAGE IN SORT ROUTINE C REAL LOWAVE,HIWAVE,LOTIME,HITIME DOUBLE PRECISION OLDERF,ERLIM,ERF,RERF INTEGER ICONRD,I,J,NIT CHARACTER LIN(5)*80,FILNAM*12,PMVAR*12,PARMSV*12,PAS*4,README*12, X PARLST*12 C C C**** OPEN MASTER CONTROL FILE ICONRD=19 README='PCONTROL.FIL' OPEN(UNIT=ICONRD,FILE=README) C C**** INITIALIZE ALL COMMON VARIABLES 100 CALL COMZER C C**** READ MASTER CONTROL FILE CALL C0NRD(ICONRD,FILNAM,PMVAR,LOWAVE,HIWAVE,LOTIME,HITIME, X PARMSV) IF(INDEX(FILNAM,'***END***»).GT.O) GO TO 32767 C C**** OPEN FILE FOR INTERMEDIATE PARAMETER VALUES IF (INDEX(PMVAR,'F').EQ.O) GOTO 120 PARLST=PARMSV(1:(INDEX(PARMSV,».')))//'IPM' 0PEN(UNIT=67,FILE=PARLST,STATUS='NEW') WRITE(67,*)'INTERMEDIATE PARAMETER VALUES FOR FILE ', FILNAM WRITE(67,*) PMVAR C 120 CONTINUE C C**** READ A SPECTRUM CALL SPEKRD(FILNAM,LIN,LOWAVE,HIWAVE,LOTIME,HITIME) C C**** OPTIMIZE FOR LIFETIMES PAS='TIME* 0LDERF=1E10 ERLIM=lE-5 N=NCOMP NIT=0 ERF=0 DO 410 I=1,NC0MP P(1,I)=SURPRM(I,1) 410 CONTINUE CALL SIMPLX(PAS,OLDERF,ERLIM,NIT,ERF,PMVAR) C C**** OPTIMIZE FOR SELECTED PARAMETERS PAS='SURF' 0LDERF=1E10 ERLIM=lE-5 N=NC0MP*PMV CALL GAUZER 183 1=0 DO 520 J=l,NCOMP DO 510 K=1,PMV 1=1+1 P(1,I)=SURPRM(J,PMX(K)) 510 CONTINUE 520 CONTINUE C IF (INDEXCPMVAR.'QO.GT.O) GO TO 600 C CALL SIMPLX(PAS,OLDERF,ERLIM,NIT,ERF,PMVAR) C 600 CONTINUE C c**** S A V E PARAMETERS FOR REDUCED SPECTRUM RERF=0 DO 620 1=1,NTIMES DO 610 J=l,NWAVES RERF=RERF+D(J,I) 610 CONTINUE 620 CONTINUE RERF=ERF/RERF CALL PRMSVR(FILNAM,LIN,LOWAVE,HIWAVE,LOTIME,HITIME,ERF,RERF, X PMVAR,PARMSV,NIT) C IF (INDEX(PMVAR,'S').GT.O) CALL SPKSVR(PARMSV.LIN) C IF (INDEX(PMVAR,'F').GT.O) CL0SE(67) C GO TO 100 C 32767 CLOSE(ICONRD) STOP END C c SUBROUTINE COMZER C C**** INITIALIZES ALL COMMON VARIABLES C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY.WHW,NCOMP,PMV C INTEGER I,J C NWAVES=0 NTIMES=0 N=0 184 WLST=0 WLEN=0 TMST=0 TMEN=0 . DLY=0 WHW=0 NCOMP=0 PMV=0 DO 100 1=1,51 NU(I)=0 DO 10 J=l,5 SAP(I,J)=0 10 CONTINUE DO 20 J=l,30 D(I,J)=0 DP(I,J)=0 20 CONTINUE 100 CONTINUE DO 200 1=1,5 PMX(I)=5 DO 110 J=l,5 SURPRM(I,J)=0 110 CONTINUE DO 120 J=l,30 CP(I,J)=0 120 CONTINUE 200 CONTINUE DO 210 1=1,15 DA(I)=0 210 CONTINUE DO 220 1=1,25 CTAU(I)=0 220 CONTINUE RETURN END C C SUBROUTINE SIMPLX(PAS,OLDERF,ERLIM,NIT,ERF,PMVAR) C C**** SIMPLEX OPTIMIZATION FOR MINIMUM ERROR C PAS - FLAG FOR ERROR FUNCTION CALCULATION C OLDERF - PREVIOUS LOW ERROR FUNCTION VALUE C ERLIM - VALUE FOR ACCEPTABLE RELATIVE ERROR LEVEL C NIT - # ITERATIONS DONE (QUIT AFTER MAXNIT) C ERF ERROR FUNCTION VALUE C PMVAR - PARAMETERS TO HOLD CONSTANT AND FLAGS C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), 185 X NWAVES,NTIMES,N,WLST,WLEN,TMST.TMEN,DLY,WHW,NCOMP,PMV DOUBLE PRECISION CNTRD(25),TP(26),0LDP(21) DOUBLE PRECISION ALPHA,BETA,GAMMA,ERF,AK,OLDERF,ERLIM,SCALEF.PTST, X TTMP,ERRTST,PARMAX,PARZIP INTEGER PCHI,PL,PH,PNH,PR,PE,PC,I,J,IPR,IPC,NIT,MAXNIT,ENFLAG n CHARACTER PAS*4,PMVAR*12 LOCAL VARIABLES: CNTRDQ CENTROID C ALPHA — REFLECTION COEFFICIENT C BETA — EXPANSION COEFFICIENT c GAMMA — CONTRACTION COEFFICIENT c SCALEF — SCALE FACTOR TO INCREASE SIMPLEX c ENFLAG — FLAG FOR DIFFERENCES IN PARAMETER VALUES c ERF — CURRENT ERROR FUNCTION VALUE c ERRTST — NORMALIZED VALUE OF ERF-OLDERF c MAXNIT — MAXIMUM # ITERATIONS ALLOWED c OLDPQ — PREVIOUS LOW ERF VALUES FOR PARAMETERS c PARMAX — MAXIMUM ALLOWED VALUE FOR A PARAMETER c PARZIP — PARAMETER IS SET TO THIS IF > PARMAX c PCHI — ERROR FUNCTON COLUMN c PL — VECTOR WITH LOWEST CHISQUARE c PH — VECTOR WITH NEXT LOWEST CHISQUARE c PNH — VECTOR WITH NEXT HIGHEST CHISQUARE c PR — VECTOR FOR REFLECTED POINT c PE — VECTOR FOR EXPANDED POINT c PC — VECTOR FOR CONTRACTED POINT c PTST — MAXIMUM RATIO ALLOWED FOR OLDP()/P() c AK — DUMMY c PCHI=N+1 PL=1 PNH=N PH=N+1 PR=N+2 PE=N+3 PC=N+4 MAXNIT=1000 ALPHA=0.9985 GAMMA=0.4985 BETA=1.95 SCALEF=0.69 ERF=1E10 PTST=0.0001 PARMAX=lE+8 PARZIP=lE-8 C C**** GENERATE PARAMETER MATRIX [P] 1030 AKol.l DO 1038 1=2,PH DO 1036 J=1,N P(I,J)=P(1,J) IF (P(I.J).GT.PARMAX) P(I,J)=PARZIP IF ((I-J).EQ.l) P(I,J)=AK*P(I,J) 186 1036 CONTINUE 1038 CONTINUE C C**** COMPUTE ERROR FUNCTION FOR EACH VECTOR IN [P] DO 1080 IPR=1,PH DO 1070 IPC=1,N CTAU(IPC)=P(IPR,IPC) 1070 CONTINUE CALL ERFKAL(ERF,PAS) P(IPR,PCHI)=ERF IF (ERF .GE. OLDERF) GOTO 1078 OLDERF=ERF DO 1076 I=1,PCHI OLDP(I)=P(IPR,I) 1076- CONTINUE 1078 CONTINUE 1080 CONTINUE C 1100 CONTINUE C**** SORT [P] TO INCREASING CHISQUARE • C CALL SUPSRT(PCHI,PCHI,PCHI,P) C 1230 PL=1 PH=N+1 PNH=N C C**** CALCULATE CENTROID DO 1318 1=1,N CNTRD(I)=-P(PH,I) DO 1316 J=1,PH CNTRD(I)=CNTRD(I)+P(J,I) 1316 CONTINUE CNTRD(I)=CNTRD(I)/N 1318 CONTINUE C C**** CALCULATE REFLECTED POINT 1320 CONTINUE 1330 AK=1+ALPHA 1340 DO 1348 1=1,N P(PR,I)=AK*CNTRD(I)-ALPHA*P(PH,I) IF (P(PR,I).GT.PARMAX) P(PR,I)=PARZIP CTAU(I)=P(PR,I) 1348 CONTINUE CALL ERFKAL(ERF,PAS) P(PR,PCHI)=ERF C C**** TEST FOR HIGH REFLECTION SUCCESS - EXPAND IF SO 1410 IF (P(PR,PCHI)-P(PL,PCHI)) 1420,1500,1500 1420 PL=PH PH=PNH AK=1-BETA DO 1428 1=1,N P(PE,I)=BETA*P(PR,I)+AK*CNTRD(I) 187 IF (P(PE,I).GT.PARMAX) P(PE,I)=PARZIP CTAU(I)=P(PE,I) 1428 CONTINUE CALL ERFKAL(ERF,PAS) P(PE,PCHI)=ERF 1440 IF (P(PE,PCHI).LT.P(PR,PCHI)) GO TO 1460 1450 DO 1458 I=1,PCHI P(PL,I)=P(PR,I) 1458 CONTINUE GOTO 1700 1460 DO 1468 I=1,PCHI P(PL,I)=P(PE,I) 1468 CONTINUE GOTO 1700 C C**** TEST FOR REFLECTION FAILURE - CONTRACT IF SO 1500 IF (P(PR.PCHI) .LT. P(PH.PCHI)) GO TO 1600 1520 AK=1-GAMMA DO 1528 1=1,N P(PR,I)=AK*CNTRD(I)+GAMMA*P(PH,I) IF (P(PR,I).GT.PARMAX) P(PR,I)=PARZIP CTAU(I)=P(PR,I) 1528 CONTINUE 1530 CALL ERFKAL(ERF,PAS) P(PR,PCHI)=ERF 1540 IF (P(PR.PCHI) .GT. P(PL.PCHI)) GOTO 1560 1550 PL=PH PH=PNH DO 1558 I=1,PCHI P(PL,I)=P(PR,I) 1558 CONTINUE GOTO 1700 1560 IF (P(PR,PCHI) .GE. P(PH,PCHI)) GOTO 1800 C C *** IF MODERATE SUCCESS REFLECT AGAIN 1600 DO 1618 I=1,PCHI P(PH,I)=P(PR,I) 1618 CONTINUE IF (P(PR,PCHI)-P(PNH,PCHI)) 1100,1100,1320 C C *** TEST FOR CONVERGENCE 1700 CONTINUE ERF=P(PL,PCHI) IF (INDEX(PMVAR,'F').EQ.O) GOTO 1708 J=NCOMP*PMV WRITE(67,*)'AT ITERATION ',NIT,(P(PL,I), I=1,PCHI) 1708 CONTINUE IF (ERF.LT.1E-20) GO TO 1999 1710 NIT=NIT+1 ERRTST=DABS((P(PL,PCHI)-OLDERF)/P(PL,PCHI)) IF (P(PL.PCHI) .GE. OLDERF) GOTO 1718 OLDERF=P(PL,PCHI) ENFLAG=0 DO 1716 1=1,PCHI 188 TTMP=DABS((0LDP(I)/P(PL,I))-1.0) IF(TTMP.GT.PTST) ENFLAG=1 OLDP(I)=P(PL,I) 1716 CONTINUE 1718 CONTINUE IF (NIT.GT.MAXNIT) GO TO 1999 1720 IF ((ERRTST-ERLIM).GT.0.0) GOTO 1100 C C**** TEST FOR DIFFERENCES BETWEEN OLD AND NEW PARAMETERS IF (ENFLAG.GT.O) GOTO 1100 GOTO 1999 C *** SCALE UP 1800 NIT=NIT+1 IF(NIT.GT.MAXNIT) GO TO 1999 DO 1838 11=1,PCHI DO 1836 J=1,N P(II,J)=P(II,J)+SCALEF*(P(PL,J)-P(II,J)) IF (P(II.J).GT.PARMAX) P(II,J)=PARZIP CTAU(J)=P(II,J) 1836 CONTINUE 1838 CONTINUE GO TO 1100 C C *** RETURN TO MAIN PROGRAM 1999 RETURN END C c SUBROUTINE ERFKAL(ERF,PAS) C C *** MAIN SUBROUTINE FOR COMPUTING ERROR FUNCTION C ERF - ERROR FUNCTION VALUE C PAS - FLAG: 'SURF' = FIT SURFACE WITHIN BOUNDS C *STRP' = STRIP & FIT C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY,WHW,NCOMP,PMV C DOUBLE PRECISION ERF CHARACTER PAS*4 C C**** NO NEGATIVES PERMITTED FOR ANY PARAMETERS DO 50 1=1,N IF (CTAU(I).LT.O) THEN ERF=1E10 RETURN END IF 50 CONTINUE 189 c IF (PAS.EQ.'SURF') GOTO 200 C 100 CALL TAUE'ST CALL DPEST CALL CHISQU(ERF) RETURN C 200 CALL TAUNON CALL DPEST CALL CHISQU(ERF) RETURN END C C SUBROUTINE DPEST C C *** COMPUTES TRIAL DATA MATRIX: [D'] = [SAP] * [C] C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU.P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES, NTIMES, N, WLST, WLEN, TMST, TMEN, DLY, WHW, NCOMP, PMV C INTEGER I,J,K C DO 2208 1=1,NWAVES DO 2206 J=l,NTIMES DP(I,J)=0 DO 2204 K=l,NCOMP DP(I,J)=DP(I,J)+SAP(I,K)*CP(K,J) 2204 CONTINUE 2206 CONTINUE 2208 CONTINUE RETURN END C c SUBROUTINE CHISQU(ERF) C C *** COMPUTE ERROR BETWEEN ARAYS [D] AND [D1] C ERF - ERROR FUNCTION VALUE C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), 190 X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY.WHW,NCOMP,PMV C INTEGER I,J DOUBLE PRECISION CHISQ,A,PNEG,SUM,SUMNEG,ERF C C**** LOCAL VARIABLES: CHISQ - SUM DIFFERENCES SQARED C PNEG - PENALTY MULTIPLIER FOR NEGATIVE VALUES 2310 CHISQ=0 DO 2308 I=WLST,WLEN DO 2306 J=TMST,TMEN A=D(I,J)-DP(I,J) CHISQ=CHISQ+A*A 2306 CONTINUE 2308 CONTINUE C C *** PENALIZE FOR NEGATIVE VALUES IN [SAP] 2330 PNEG=100 SUM=0 SUMNEG=0 2340 DO 2348 I=WLST,WLEN DO 2346 J=l,NCOMP SUM=SUM+SAP(I,J) IF (SAP(I,J)) 2344,2345,2345 2344 SUMNEG=SUMNEG-SAP(I,J) 2345 CONTINUE 2346 CONTINUE 2348 CONTINUE 2350 ERF=DABS(CHISQ*(1+PNEG*SUMNEG/SUM)) 2360 RETURN END C c SUBROUTINE TAUEST C C *** COMPUTES MATRIX [SAP] FOR CASE WHERE WE WANT TO FIND LIFETIMES C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY.WHW,NCOMP,PMV C INTEGER I,J,K DOUBLE PRECISION CPT(30,5),MXI(25,25),WFW,ZA,ZB,TTA,TTB C C *** COMPUTE [SAP] = [D] * [C']T * ([C] * [C ]T)INVERSE C C *** COMPUTE LIFETIME MATRIX [C] WFW=2.0*WHW DO 2118 1=1,NTIMES TTA=-DLY*I 191 TTB=TTA-WFW DO 2116 J=1,N ZA=TTA/CTAU(J) ZB=TTB/CTAU(J) IF (ZA.GT.69) ZA=69 IF (ZA.LT.-69) ZA=-69 IF (ZB.GT.69) ZB=69 IF (ZB.LT.-69) ZB=-69 CP(J,I)=CTAU(J)*(DEXP(ZA)-DEXP(ZB)) 2116 CONTINUE 2118 CONTINUE C C *** COMPUTE THE PSEUDOINVERSE: ([C] * [C ]T)INVERSE DO 2138 1=1,N DO 2136 J=1,N MXI(I,J)=0 DO 2134 K=l,NTIMES MXI(I,J)=MXI(I,J)+CP(I,K)*CP(J,K) 2134 CONTINUE 2136 CONTINUE 2138 CONTINUE CALL MXINVT(N.MXI) C C *** COMPUTE: [CPT] = [C']T *.([C*] * [C]T)INVERSE DO 2168 1=1,NTIMES DO 2166 J=1,N CPT(I,J)=0 DO 2164 K=1,N CPT(I,J)=CPT(I,J)+CP(K,I)*MXI(K,J) 2164 CONTINUE 2166 CONTINUE 2168 CONTINUE C C *** COMPUTE: [SAP] = [D] * [CPT] DO 218 1=1,NWAVES DO 2186 J=1,N SAP(I,J)=0 DO 2184 K=l,NTIMES SAP(I,J)=SAP(I,J)+D(I,K)*CPT(K,J) 2184 CONTINUE 2186 CONTINUE 218JI CONTINUE RETURN END C c SUBROUTINE TAUNON C C *** COMPUTES MATRIX [SAP] FOR CASE WHERE LIFETIMES ARE KNOWN C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN 192 c COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY,WHW,NCOMP,PMV C REAL Z,T INTEGER I,J,K DOUBLE PRECISION WFW,TTA,TTB,ZA,ZB C C *** PUT CTAU VALUES INTO SURFACE PARAMATER MATRIX 1=0 DO 8418 J=l,NCOMP DO 8416 K=1,PMV 1=1+1 SURPRM(J,PMX(K))=CTAU(I) d 1416 CONTINUE 8418 CONTINUE C C *** COMPUTE LIFETIME MATRIX [C] WFW=2.0*WHW DO 4118 1=1,NTIMES TTA=-DLY*I TTB=TTA-WFW DO 4116 J=l,NCOMP ZA=TTA/SURPRM(J,1) ZB=TTB/SURPRM(J,1) IF (ZA.GT.69) ZA=69 IF (ZA.LT.-69) ZA=-69 IF (ZB.GT.69) ZB=69 IF (ZB.LT.-69) ZB=-69 CP(J,I)=SURPRM(J,1)*(DEXP(ZA)-DEXP(ZB)) 4116 CONTINUE 4118 CONTINUE C C *** COMPUTE [SAP] FROM GAUSS PARAMETERS DO 4158 J=l,NCOMP DO 4156 1=1,NWAVES Z=(NU(I)-SURPRM(J,2))/SURPRM(J,3) ZA=-.5*Z*Z IF (ZA.GT.69) ZA=69 IF (ZA.LT.-69) ZA=-69 SAP(I,J)=SURPRM(J,4)*DEXP(ZA) 4156 CONTINUE 4158 CONTINUE RETURN END C C SUBROUTINE SUPSRT(N,C,NSC,P) C C**** SORTS MATRIX IN ASCENDING ORDER FOR A GIVEN COLUMN C N - # ROWS 193 C C - # COLUMNS C NSC SORTING COLUMN C P(N,C) - ARRAY TO SORT C DOUBLE PRECISION P(30,21),TP(30) INTEGER N,C,NSC,D,I,J,K,JD,IP,IMD,IPD.NMD,DMINUS C D=2**INT(ALOG(REAL(N))/ALOG(2.))-l 1120 NMD=N-D DO 1210 1=1,NMD IPD=I+D IF (P(I,NSC).LT.P(IPD,NSC)) GO TO 1210 1140 IP=I+D DO 1145 K=1,C TP(K)=P(IP,K) P(IP,K)=P(I,K) 1145 CONTINUE 1150 IF (I.LT.D) THEN 1155 DO 1158 K=1,C P(I,K)=TP(K) 1158 CONTINUE GO TO 1210 END IF 1160 IMD=I-D DMINUS=-D DO 1190 J=IMD,1,DMINUS IF (TP(NSC).GT.P(J,NSC)) GO TO 1200 1180 JD=J+D DO 1185 K=1,C P(JD,K)=P(J,K) 1L 5 CONTINUE 1190 CONTINUE 1200 JD=J+D DO 1205 K=1,C P(JD,K)=TP(K) 1205 CONTINUE 1210 CONTINUE 1220 D=D/2 1230 IF (D.GT.O) GO TO 1120 1300 RETURN END C c SUBROUTINE MXINVT(N,MXI) C C**** INVERTS MATRIX C N - # ROWS IN SQUARE MATRIX C MXI(N,N) - MATRIX TO BE INVERTED C INTEGER N,I,J,K,L,M,PV(25,3),IR,IC,JR,JC DOUBLE PRECISION MXI(25,25),MAX,P,S,T C 194 C NOTES ON DIMENSIONS: DIMENSION MXI(5*NCOMP,5*NCOMP),PV(5*NC0MP,3) C NCOMP IS THE MAXIMUM # OF COMPONENTS FOR PROGRAM C ASSUME NCOMP IS 5. C C INITIALIZE PV DO 20 1=1,N DO 10 J=l,3 PV(I,J)=0 10 CONTINUE 20 CONTINUE C DO 360 1=1,N MAX=0 DO 170 J=1,N IF(PV(J,3)-1) 100,170,100 100 DO 160 K=1,N IF(PV(K,3)-1) 120,160,120 120 IF(MAX-DABS(MXI(J,K))) 130,160,160 130 IR=J IC=K MAX=DABS(MXI(J,K)) 160 CONTINUE 170 CONTINUE PV(IC,3)=PV(IC,3)+1 PV(I,1)=IR PV(I,2)=IC IF(IR-IC) 220,270,220 220 DO 260 L=1,N S=MXI(IR,L) MXI(IR,L)=MXI(IC,L) MXI(IC,L)=S 260 CONTINUE 270 P=MXI(IC,IC) MXI(IC,IC)=1 DO 295 L=1,N MXI(IC,L)=MXI(IC,L)/P 295 CONTINUE DO 350 M=1,N IF(M-IC) 320,350,320 320 T=MXI(M,IC) MXI(M,IC)=0 DO 345 L=1,N MXI(M,L)=MXI(M,L)-MXI(IC,L)*T 345 CONTINUE 350 CONTINUE 360 CONTINUE DO 470 1=1,N L=N-I+1 IF(PV(L,1)-PV(L,2)) 400,470,400 400 JR=PV(L,1) JC=PV(L,2) DO 460 K=1,N S=MXI(K,JR) MXI(K,JR)=MXI(K,JC) 195 MXI(K,JC)=S 460 CONTINUE 470 CONTINUE RETURN END C C SUBROUTINE GAUZER C C**** COMPUTES SPECTRUM PARAMETERS ASSUMING GAUSSIAN PEAKS C DOUBLE PRECISION SAP,CP,D,DP,CTAU.SURPRM,DLY.WHW,DA,NU.P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY,WHW,NCOMP,PMV C DOUBLE PRECISION SATMP(51),Q0,Q1,Q2,Q3.Q4,SKEW,KURT,EM1P,EM2P,EM3P X,EM4P,EM3,EM4 INTEGER I,J,K,LMAX,MINRT,MINLFT C C LOCAL VARIABLES: LMAX - MAXIMUM VALUE IN SPECTRUM C MINLFT - MINIMUM TO LEFT SIDE OF LMAX C MINRT - MINIMUM TO RIGHT SIDE OF LMAX C SKEW - SKEWNESS IN GAUSSIAN C KURT - KURTOSIS IN GAUSSIAN C SATMP()- DUMMY, SPECTRUM VECTOR FOR ONE EMITTER C DO 800 1=1,NCOMP DO 100 J=l,NWAVES SATMP(J)=SAP(J,I) IF (SATMP(J).LE.O) SATMP(J)=lE-8 100 CONTINUE CALL SVSMTH(NWAVES.SATMP) DO 110 J=l,NWAVES IF (SATMP(J).LE.O) SATMP(J)=lE-8 110 CONTINUE C C**** FIND MAXIMA, THEN LOCAL MINIMA ON EACH SIDE C LMAX=1 DO 200 J=l,NWAVES IF (SATMP(J).GT.SATMP(LMAX)) LMAX=J 200 CONTINUE DO 210 J=LMAX,NWAVES-1 MINRT=J IF (SATMP(J).LT.SATMP(J+1)) GO TO 220 210 CONTINUE 220 DO 230 J=LMAX,2,-1 MINLFT=J IF (SATMP(J).LT.SATMP(J-l)) GO TO 240 196 230 CONTINUE 240 CONTINUE C C**** COMPUTE SUMS 00=0 Q1=0 02=0 Q3=0 Q4=0 DO 300 J=MINLFT,MINRT QO=QO+SAP(J,I) Q1=Q1+SAP(J,I)*NU(J) Q2=Q2+SAP(J,I)*NU(J)*NU(J) Q3=Q3+SAP(J,I)*NU(J)*NU(J)*NU(J) Q4=Q4+SAP(J,I)*NU(J)*NU(J)*NU(J)*NU(J) 300 CONTINUE C C**** SUBSTITUTE VALUES INTO SURFACE PARAMETER ARRAY C SURPRM(I,1)=CTAU(I) SURPRM(I,2)=Q1/Q0 SURPRM(I,3)=DSQRT(DABS((Q2/Q0)-(SURPRM(1,2)*SURPRM(1,2)))) SURPRM(1,4)=SATMP(LMAX) EM1P=Q1/Q0 EM2P=Q2/Q0 EM3P=Q3/Q0 EM4P=Q4/Q0 EM3=EM3P - 3*EM1P*EM2P + 2*EM1P**3 EM4=EM4P - 4*EM1P*EM3P + 6*EM2P*EM1P**2 - 3*EM1P**4 SKEW=EM3/(SURPRM(I,3)**3) KURT=EM4/(SURPRM(I,3)**4) SURPRM(I,5)=SKEW C C**** JUST IN CASE THE MATH WENT WILD IF(SURPRM(I,2).GT.NU(1)) THEN SURPRM(I,2)=NU(1) SURPRM(I,3)=0.1*SURPRM(1,2) SURPRM(I,4)=SATMP(LMAX) END IF IF(SURPRM(I,2).LT.NU(NWAVES)) THEN SURPRM(1,2)=NU(NWAVES) SURPRM(I,3)=0.1*SURPRM(1,2) SURPRM(I,4)=SATMP(LMAX) END IF C 800 CONTINUE RETURN END C Q * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Q * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * C SUBROUTINE SVSMTH(NW.RAW) C 197 C**** SAVITZKY-GOLAY 5 POINT SMOOTHING - RETURNS SMOOTHED DATA VECTOR C NOTE: FIRST TWO AND LAST TWO ELEMENTS OF DATA VECTOR ARE SET TO ZERO! C NW - # ELEMENTS IN VECTOR C RAW(NW) - VECTOR TO SMOOTH C INTEGER I,J,K,KA,MS,NW DOUBLE PRECISION RAW(51),SMTHD(51),PTS(5) C C**** INITIALIZE C MS=NW-4 DO 100 1=2,5 J=I-1 PTS(I)=RAW(J) 100 CONTINUE DO 110 1=1,NW SMTHD(I)=0 110 CONTINUE C C**** SMOOTH C DO 300 1=1,MS J=I+4 DO 200 K=l,4 KA=K+1 PTS(K)=PTS(KA) 200 CONTINUE PTS(5)=RAW(J) SMTHD(I+2)=(-3*PTS(l)+12*PTS(2)+17*PTS(3)+12*PTS(4)-3*PTS(5))/35 300 CONTINUE C C**** SUBSTITUTE SMOOTHED VECTOR TO RAW VECTOR DO 400 1=1, NW RAW(I)=SMTHD(I) 400 CONTINUE RETURN END C C SUBROUTINE RESPLN(A0,A1,A2) C C *** COMPUTES PLANE EQUATION FOR RESIDUALS: [R] = [DA] - [DP] C C *** EQUATION IS: Z = AO + A1*X + A2*Y C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY.WHW,NCOMP,PMV C 198 INTEGER I.J.K DOUBLE PRECISION T,EN,SR,SX,SY,SX2,SY2,SXR,SYR,SXY,AO,Al,A2,DE C C *** SUM SUMS: C EN=0 SR=0 SX=0 SY=0 SX2=0 SY2=0 SXR=0 SYR=0 SXY=0 DO 210 J=TMST,TMEN T=DLY*J+WHW DO 200 I=WLST,WLEN R=D(I,J)-DP(I,J) EN=EN+1.0 SR=SR+R SX=SX+NU(I) SY=SY+T SX2=SX2+NU(I)*NU(I) SY2=SY2+T*T SXR=SXR+NU(I)*R SYR=SYR+T*R SXY=SXY+NU(I)*T 200 CONTINUE 210 CONTINUE C C *** COMPUTE LEAST SQUARES PLANE COEFFECIENTS C DE=EN*SX2*SY2-EN*SXY*SXY-SX*SX*SY2+SX*SXY*SY+SY*SX*SXY-SY*SX2*SY A0=(SR*SX2*SY2-SR*SXY*SXY-SX*SXR*SY2+SX*SXY*SYR+SY*SXR*SXY-SY*SX2* XSYR)/DE A1=(EN*SXR*SY2-EN*SXY*SYR-SR*SX*SY2+SR*SXY*SY+SY*SX*SYR-SY*SXR*SY) X/DE A2=(EN*SX2*SYR-EN*SXR*SXY-SX*SX*SYR+SX*SXR*SY+SR*SX*SXY-SR*SX2*SY) X/DE C RETURN END C r j * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ^ c SUBROUTINE PRMSVR(FILNAM,LIN,LOWAVE,HIWAVE,LOTIME,HITIME,ERF,RERF, XPMVAR,PARMSV,NIT) C C**** SAVES PARAMETERS FOR REDUCED SPECTRUM C FILNAM - FILE NAME OF ORIGINAL DATA FILE C LIN() - DESCRIPTIVE FILE DATA C LOWAVE - LOW WAVELENGTH OF DATA REDUCTION WINDOW C HIWAVE - HIGH WAVELENGTH " 199 C LOTIME - LOW TIME " C HITIME - HIGH TIME " C ERF - ERROR - SUM OF SQUARED DIFFERENCES C RERF - RELATIVE ERROR C PMVAR - PARAMETERS TO HOLD CONSTANT & FLAGS C PARMSV - SPECTRUM PARAMETER FILE NAME C NIT - # ITERATIONS C AO TERM IN RESIDUALS PLANE: Z=AO + A1*TIME + A2*WAVELENGTH C Al C A2 C 11 II C c DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY,WHW,NCOMP,PMV DOUBLE PRECISION ERF,RERF,AO,Al,A2 REAL LOWAVE,HIWAVE,LOTIME,HITIME INTEGER I,MOUT,NIT CHARACTER FILNAM*12,LIN(5)*80,PMVAR*12,PARMSV*12,BRDR*12 M0UT=12 OPEN(UNIT=M0UT,FILE=PARMSV, STATUS='NEW *) WRITE(M0UT,10) PARMSV 10 FORMATCSIMPLEX OPTIMIZED PARAMETERS FOR FILE ',A12) DO 200 1=1,5 WRITE(MOUT,*) LIN(I) 20 FORMAT(1X,A80) 200 CONTINUE WRITE(M0UT,30) ERF 30 FORMAT(IX,'ERROR FUNCTION = '.E15.5) WRITE(MOUT,AO) RERF 40 FORMAT(IX,'RELATIVE ERROR = \E15.5) WRITE(MOUT,50) NIT,PMVAR 50 F0RMAT(1X,I5,' ITERATIONS, CONSTANT PARAMETERS: \A12) CALL RESPLN(A0,A1,A2) WRITE(M0UT,53) A0.A1.A2 53 F0RMAT(IX,'RESIDUAL PLANE: AO, Al, A2 =', 3D15.5) WRITE(MOUT,60) LOWAVE,HIWAVE 60 FORMAT(IX,'SPECTRUM WINDOW:',F10.1,' TO ',F10.1,' ANGSTROMS') WRITE(M0UT,70) LOTIME,HITIME 70 F0RMAT(1X,1 ',F10.5,' TO \F10.5,' MICROSECONDS') WRITE(MOUT,*)'COMPONENT ',1=1,NCOMP) 80 FORMAT(IX,'COMPONENT ',5115) WRITE(MOUT,*)'LIFETIME, US ', (SURPRM(I,1), 1=1,NCOMP) 90 FORMAT(IX,'LIFETIME, US \5E15.6) WRITE(MOUT,*)'PEAK MAXIMA, 1/ANGSTROMS ', (SURPRM(I,2), 1=1,NCOMP) 100 FORMAT(IX,1PEAK MAXIMA, 1/ANGSTROMS \5E15.6) WRITE(MOUT,*)'PEAK S.DEV., 1/ANGSTROMS ', (SURPRM(I,3), 1=1,NCOMP) 110 FORMAT(IX,1PEAK S.DEV., 1/ANGSTROMS \5E15.6) 200 WRITE(MOUT,*)'PEAK INTENSITY \ (SURPRM(I,4), 1=1,NCOMP) 120 FORMAT(IX,'PEAK INTENSITY \5E15.6) WRITE(MOUT,*)»PEAK ASSYMETRY *, (SURPRM(I,5), 1=1,NCOMP) 130 FORMAT(IX,'PEAK ASSYMETRY \5E15.6) BRDR='************1 WRITE(M0UT,140) (BRDR,J=1,6) 140 F0RMAT('0',6A12) C CLOSE(MOUT) WRITE(*,*)'FILE ',PARMSV,' SAVED' RETURN END C Q$$$$4$:£4:jc:je43ie:jc$:{e:je$:je3Jc:M:*****^ c SUBROUTINE SPEKRD(FILNAM,LIN,LOWAVE,HIWAVE,LOTIME,HITIME) C C**** READ A SPECTRUM, SET BOUNDS FOR DATA REDUCTION REGION IN SPECTRUM C FILNAM - FILE NAME OF ORIGINAL DATA FILE C LIN() - DESCRIPTIVE FILE DATA C LOWAVE - LOW WAVELENGTH OF DATA REDUCTION -WINDOW C HIWAVE - HIGH WAVELENGTH " C LOTIME - LOW TIME " C HITIME - HIGH TIME " C DOUBLE PRECISION SAP,CP,D,DP,CTAU.SURPRM,DLY.WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY.WHW,NCOMP,PMV C C REAL STWL,ENWL,INWL,ALAM,LOWAVE,HIWAVE,LOTIME,HITIME INTEGER MIN,I,J,NTT CHARACTER FILNAM*12,LIN(5)*80 C WRITE(*,*)'WORKING HARD ON FILE '.FILNAM MIN=10 OPEN(UNIT=MIN,FILE=FILNAM) C DO 100 1=1,5 READ(MIN.IO) LIN(I) 10 F0RMAT(A80) 100 CONTINUE C DO 200 1=6,13 READ(MIN,*) DA(I) 200 CONTINUE C STWL=DA(10) ENWL=DA(11) INWL=DA(12) 201 IF (STWL.GT.ENWL) THEN STWL=DA(11) ENWL=DA(10) END IF WHW=0.5*DA(13) DLY=DA(6)*DA(7) NTIMES=DA(9) NWAVES=(ENWL-STWL+INWL)/INWL ALAM=STWL-INWL DO 300 1=1,NWAVES ALAM=ALAM+INWL NU(I)=1/ALAM 300 CONTINUE C DO 410 1=1,NWAVES DO 400 J=l,NTIMES READ(MIN,*) D(I,J),X,X,X 40 F0RMAT(F8.4,2X,F8.4,2X,F8.2,2X,F8.2) 400 CONTINUE 410 CONTINUE C CLOSE(UNIT=MIN) C C *** CHECK BOUNDS FOR LIMITING AREA OF SPECTRUM FOR DATA REDUCTION IF ((LOWAVE.LT.STWL).OR.(LOWAVE.GT.ENWL)) THEN LOWAVE=STWL WLST=1 END IF IF ((HIWAVE.LT.STWL).OR.(HIWAVE.GT.ENWL)) THEN HIWAVE=ENWL WLEN=NWAVES END IF IF (HIWAVE.LT.LOWAVE) THEN LOWAVE=STWL HIWAVE=ENWL WLST=1 . WLEN=NWAVES GO TO 500 END IF NTT=INT((LOWAVE-STWL)/INWL) WLST=1+NTT LOWAVE=STWL+NTT*INWL NTT=INT((ENWL-HIWAVE)/INWL) WLEN=NWAVES-NTT HIWAVE=ENWL-NTT*INWL 500 CONTINUE STIM=DLY ETIM=NTIMES*DLY IF ((LOTIME.LT.STIM).OR.(LOTIME.GT.ETIM)) THEN LOTIME=STIM TMST=1 END IF IF ((HITIME.LT.STIM).OR.(HITIME.GT.ETIM)) THEN HITIME=ETIM 202 TMEN=NTIMES END IF IF (LOTIME.GT.HITIME) THEN LOTIME=STIM HITIME=ETIM TMST=1 TMEN=NTIMES GO TO 520 END IF NTT=INT((LOTIME-STIM)/DLY) TMST=1+NTT LOTIME=STIM+NTT*DLY NTT=INT((ETIM-HITIME)/DLY) TMEN=NTIMES-NTT HITIME=ETIM-NTT*DLY 520 CONTINUE RETURN END C c SUBROUTINE CONRD(ICONRD,FILNAM,PMVAR,LOWAVE,HIWAVE,LOTIME,HITIME, XPARMSV) C C**** READS MASTER CONTROL FILE - TELLS WHAT FILES TO READ & WHAT TO C HOLD CONSTANT & SPECTRUM WINDOW TO C OPTIMIZE OVER. C ICONRD - UNIT # FOR CONTROL FILE C FILNAM - FILE NAME OF ORIGINAL DATA FILE C LOWAVE - LOW WAVELENGTH OF DATA REDUCTION WINDOW C HIWAVE - HIGH WAVELENGTH " C LOTIME - LOW TIME " C HITIME - HIGH TIME " C PARMSV - SPECTRUM PARAMETER FILE NAME C PMVAR - PARAMETERS TO HOLD CONSTANT, SET FLAGS C T - LIFETIME C M - PEAK MAXIMA C W - PEAK WIDTH C I - PEAK INTENSITY C A - PEAK ASSYMETRY C Q - QUIT AFTER FIRST STAGE C S - FLAG TO SAVE COMPUTED SPECTRUM C F - FLAG TO SAVE INTERMEDIATE PARAMETER VALUES C DOUBLE PRECISION SAP,CP,D,DP,CTAU,SURPRM,DLY,WHW,DA,NU,P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY.WHW,NCOMP,PMV C REAL LOWAVE,HIWAVE,LOTIME,HITIME INTEGER ICONRD 203 CHARACTER FILNAM*12,BASEFL*12,PMVAR*12,PARMSV*12 C 90 CONTINUE C C**** FILE TO READ READ(ICONRD.IOO) FILNAM 100 F0RMAT(A12) IF(INDEX(FILNAM,»***END***').GT.O) RETURN IF(INDEX(FILNAM,' ').GT.O) FILNAM=FILNAM(1:(INDEX(FILNAM,* f))-l) C C**** FILE TO STORE REDUCED PARAMETERS READ(IC0NRD,110) BASEFL 110 F0RMAT(A12) IF(INDEX(BASEFL,'*t).GT.O) BASEFL=FILNAM(1:» ) IF(INDEX(BASEFL,' ').GT.O) BASEFL=BASEFL(1:(INDEX(BASEFL,* f))-l) IF(INDEX(BASEFL,\').GT.O) BASEFL=BASEFL(1:(INDEX(BASEFL,'.'))-l) IF(LEN(BASEFL) .GT.i ) THEN PARMSV=BASEFL( 1 ) // *. SLP' GO TO 115 END IF PARMSV=BASEFL//'.SLP' 115 CONTINUE C C**** SET PARAMETERS TO VARY IN SIMPLEX OPTIMIZATION READ(ICONRD,120) PMVAR 120 F0RMAT(A12) PMV=0 IF(INDEX(PMVAR,'T»).EQ.O) THEN C**** VARY LIFETIMES PMV=1 PMX(PMV)=1 END IF IF(INDEX(PMVAR,'M,).EQ.O) THEN C**** VARY PEAK MAXIMA PMV=PMV+1 PMX(PMV)=2 END IF IF(INDEX(PMVAR,'W').EQ.O) THEN C**** VARY PEAK WIDTH (STANDARD DEVIATION) PMV=PMV+1 PMX(PMV)=3 END IF IF(INDEX(PMVAR,'I').EQ.O) THEN C**** VARY PEAK PRE-EXPONENTIAL INTENSITY FACTOR PMV=PMV+1 PMX(PMV)=4 END IF IF(INDEX(PMVAR,,A').EQ.O) THEN C**** VARY PEAK ASSYMETRY PMV=PMV+1 PMX(PMV)=5 END IF C C**** NUMBER OF EMITTING COMPONENTS IN SPECTRUM 204 READ(ICONRD,*) NCOMP 130 FORMAT(15) C C**** SURFACE PARAMETERS FOR EACH EMITTING COMPONENT DO 150 1=1,NCOMP READ(ICONRD,*) (SURPRM(I,J),J=l,5) 140 F0RMAT(5G15.6) 150 CONTINUE C C**** BOUNDARIES FOR LIMITING OPTIMIZATION TO A REGION OF SPECTRUM READ(ICONRD,*) LOWAVE,HIWAVE,LOTIME,HITIME 160 F0RMAT(4G15.6) C C**** SKIP TO NEXT SPECTRUM IF A ".SLP" FILE EXISTS 0PEN(UNIT=69,ERR=200,FILE=PARMSV,STATUS='OLD') WRITE(*,*) 'SKIPPING FILE '.FILNAM,' - FILE \PARMSV,' FOUND' GO TO 90 C 200 CONTINUE C C**** SKIP TO NEXT SPECTRUM IF THE DATA FILE DOES NOT EXIST 0PEN(UNIT=69,ERR=220,FILE=FILNAM,STATUS='OLD') GO TO 300 220 WRITE(*,*) 'FILE '.FILNAM,' DOES NOT EXIST' GO TO 90 C 300 CONTINUE RETURN END C c SUBROUTINE SPKSVR(PARMSV,LIN) C C**** SAVES COMPUTED AND ORIGINAL SPECTRA C PARMSV - SPECTRUM PARAMETER FILE NAME C LIN() - DESCRIPTIVE DATA C DOUBLE PRECISION SAP,CP,D,DP,CTAU.SURPRM,DLY.WHW,DA,NU.P INTEGER N,NTIMES,NWAVES,NCOMP,PMV,PMX,WLST,WLEN,TMST,TMEN C COMMON CP(5,30),CTAU(25),D(51,30),DP(51,30),DA(15),NU(51), X P(30,21),SAP(51,5),SURPRM(5,5),PMX(5), X NWAVES,NTIMES,N,WLST,WLEN,TMST,TMEN,DLY.WHW,NCOMP,PMV C C INTEGER MOOT,I,J REAL X,Y CHARACTER FILNAM*12,LIN(5)*80,PARMSV*12 C FILNAM=PARMSV(1:INDEX(PARMSV,'.'))//'SSP' Y=1.0 C 205 M0UT=22 OPEN(UNIT=MOUT, FILE=FILNAM, STATUS='NEW') WRITE(MOUT,*) 'COMPUTED \FILNAM 20 F0RMAT(1X,A12) DO 800 1=1,4 WRITE(MOUT,*) LIN(I) 800 CONTINUE 30 FORMAT (1X.A18) DO 810 1=6,13 WRITE(M0UT,35) DA(I) 35 F0RMAT(1X,E15.5) 810 CONTINUE DO 830 1=1, NWAVES DO 820 J=l,NTIMES X=D(I,J)-DP(I,J) WRITE(M0UT,40) X,DP(I,J),D(I,J),Y 40 F0RMAT(1X,F8.4,2X,F8.4,2X,F8.4,2X,F8.4) 820 CONTINUE 830 CONTINUE CLOSE(MOUT) RETURN END 206 

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