UBC Theses and Dissertations
Far-infrared reflectivity measurements including thin films of ice and a mosaic of TTF-TCNQ crystals Kornelsen, Kevin E.
The main objective of this thesis project involved the design and construction of a reflectance module to be used with a far infrared Fourier spectrometer. This module would be used for specular reflectivity measurements with small samples at temperatures between liquid helium and room temperature. Early tests of this reflectance module were used to investigate some of the interesting changes in the far infrared spectrum which result from ice condensation on the sample surface. With the condensing substrate at temperatures between 130 and 200K the condensation is in a crystalline phase and can drastically reduce the intensity of the reflected radiation. The effects are most significant in the spectral range between 150 and 300cm⁻¹. Substrate temperatures lower than 130K lead to condensation of ice in a vitreous phase which does not have such a large effect on the far infrared spectrum. Modifications were made to the reflectance module design to eliminate the unpredictable effects of ice condensation and a final set of tests were performed measuring the reflectance of a mosaic of TTF-TCNQ crystals. The resulting data shows much of the fine structure which has been observed in other measurements using bolometric techniques.
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