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Precision Measurements of Magnetic Penetration Depth in Precision Measurements of Magnetic Penetration Depth in YB[sub a]₂Cu₃0₇₋[sub δ] Kamal, Saeid
Abstract
Using sensitive cavity perturbation techniques, we have performed extensive measurements of the microwave surface impedance of high quality single crystals of YB[sub a]₂Cu₃0₇₋[sub δ]. We have employed a novel loop-gap resonator with operating frequency at about 1 GHz and quality factor of 1 x 10⁶ to 4 x 10⁶ to probe the electrodynamics of the superconducting state of YB[sub a]₂Cu₃0₇₋[sub δ]. The main focus of the thesis has been on the precision measurements of the magnetic penetration depth. We have studied the superconducting region of the phase diagram of YB[sub a]₂Cu₃0₇₋[sub δ] by measuring single crystals with various amounts of oxygen doping, ranging from underdoped ortho-II phase (δ = 0.5) to the fully oxygenated (δ = 0; slightly overdoped). The role of impurities have been studied by introducing controlled amounts of Zn, Ni, and Ca impurities into the crystals. A new generation of ultra high purity single crystals were grown at UBC using BaZrOa crucibles. Observation of extremely long quasiparticle scattering times in these higher purity crystals opened a new chapter in microwave spectroscopy of quasiparticles in YB[sub a]₂Cu₃0₇₋[sub δ] at our laboratory. Measurements of magnetic penetration depth performed in this thesis have been a continuous contributing factor to these studies. Also careful measurements of magnetic penetration depth near the transition temperature T[sub c]₁, has revealed non-mean field behaviour consistent with 3D-XY critical fluctuations.
Item Metadata
Title |
Precision Measurements of Magnetic Penetration Depth in Precision Measurements of Magnetic Penetration Depth in YB[sub a]₂Cu₃0₇₋[sub δ]
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2002
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Description |
Using sensitive cavity perturbation techniques, we have performed extensive
measurements of the microwave surface impedance of high quality single
crystals of YB[sub a]₂Cu₃0₇₋[sub δ]. We have employed a novel loop-gap resonator with
operating frequency at about 1 GHz and quality factor of 1 x 10⁶ to 4 x 10⁶
to probe the electrodynamics of the superconducting state of YB[sub a]₂Cu₃0₇₋[sub δ].
The main focus of the thesis has been on the precision measurements of the
magnetic penetration depth. We have studied the superconducting region
of the phase diagram of YB[sub a]₂Cu₃0₇₋[sub δ] by measuring single crystals with
various amounts of oxygen doping, ranging from underdoped ortho-II phase
(δ = 0.5) to the fully oxygenated (δ = 0; slightly overdoped). The role
of impurities have been studied by introducing controlled amounts of Zn,
Ni, and Ca impurities into the crystals. A new generation of ultra high
purity single crystals were grown at UBC using BaZrOa crucibles. Observation
of extremely long quasiparticle scattering times in these higher purity
crystals opened a new chapter in microwave spectroscopy of quasiparticles
in YB[sub a]₂Cu₃0₇₋[sub δ] at our laboratory. Measurements of magnetic penetration
depth performed in this thesis have been a continuous contributing factor
to these studies. Also careful measurements of magnetic penetration depth
near the transition temperature T[sub c]₁, has revealed non-mean field behaviour
consistent with 3D-XY critical fluctuations.
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Extent |
10204524 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-10-01
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0085618
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2002-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.