List of Figures

• The Normal Ground State of a Metal
• Crystallographic Structure of $\mbox{YBa$_{2}$ Cu$_{3}$ O$_{7- \delta}$ }$
• Phase Diagram for $\mbox{YBa$_{2}$ Cu$_{3}$ O$_{7- \delta}$ }$
• Antiferromagnetic Square Lattice
• A Perfect Triangular Flux Lattice
• A Perfect Triangular Flux Lattice
• Sample Asymmetry Spectra
• The Asymmetry Spectrum in the Normal State
• The Temperature Dependence of the Asymmetry Spectrum
• The Temperature Dependence of the Frequency Distribution
• Changing the Field Below T_c
• Single Gaussian Fits
• Linewidth Competition
• Correlation of The Linewidth Parameters
• $\chi ^{2}$ from Global Fitting
• Background Signal Fitting Parameters
• Sample Signal Fitting Parameters
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T applied field
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T and 1.5T applied fields
• Comparison with microwave results
• Background Signal Fitting Parameters
• Sample Signal Fitting Parameters
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T and 1.5T applied fields
• Comparison with microwave results
• Background Signal Fitting Parameters
• Sample Signal Fitting Parameters
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T and 1.5T applied fields
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T and 1.5T applied fields (full scan)
• Comparison with microwave results
• The total asymmetry amplitude
• The Asymmetry Spectrum in the Normal State
• The Temperature Dependence of the Asymmetry Spectrum
• The Temperature Dependence of the Frequency Distribution
• Changing the Field Below T_c
• Single Gaussian Fits
• Linewidth Competition
• Correlation of The Linewidth Parameters
• $\chi ^{2}$ from Global Fitting
• Background Signal Fitting Parameters
• Sample Signal Fitting Parameters
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T applied field
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T and 1.5T applied fields
• Comparison with microwave results
• Background Signal Fitting Parameters
• Sample Signal Fitting Parameters
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T and 1.5T applied fields
• Comparison with microwave results
• Background Signal Fitting Parameters
• Sample Signal Fitting Parameters
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T and 1.5T applied fields
• $1/ \lambda _{ab}^{2}$ vs. T for 0.5T and 1.5T applied fields (full scan)
• Comparison with microwave results
• The total asymmetry amplitude

Acknowledgements

I would like to thank my thesis advisor Rob Kiefl for many patient and informative discussions over the past two years, all of which have accelerated my research and heightened my interest in the field of high-T_c superconductors. Equal thanks to Jess Brewer, the TRIUMF spokesperson for this experiment and the author of many of the valuable computer programs used in the analysis process.

Additional thanks to my predecessor in this work, Tanya Riseman, who provided me with the algorithm which forms the basis for the computer program I used to fit the data. I am also appreciative of the early help from Juerg Schneider, who helped design the low-background apparatus used in this experiment. For making the wonderful $\mbox{YBa$_{2}$ Cu$_{3}$ O$_{6.95}$ }$ crystals, I thank Ruixing Liang. For running shifts in this experiment and/or participating in inspirational discussions, I would like to thank Walter Hardy, Doug Bonn, Andrew MacFarlane, Gerald Morris, Kim Chow, Tim Duty, Phillipe Mendels, Jim Carolan and Arnold Sikkema. Also, thanks to Curtis Ballard and Keith Hoyle for their technical assistance.