Optical and transport properties of the high-temperature cuprate superconductor La₂₋ˣSrˣCuO₄

• Main Author: Cooper, Rosemary Alice
• Published: University of Bristol 2009
• Subjects: 537.623
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503870

This thesis describes measurements of the optical and d.c. electrical conductivity of a family of high-temperature superconductors. For this purpose, an optical spectroscopy laboratory was constructed, incorporating a commercial infrared spectrometer and a homemade continuous-flow optical cryostat. The performance of the experimental set-up was studied through comparison with recent, high-quality, reflectance data on heavily over doped La2-xSra;Cu04 (LSCO) with x = 0.28, which was measured by the Timusk group at McMaster University, Canada. Excellent agreement, to within 1%, was found and thus, a working experiment was realized. The system is capable of measurements at temperatures n the range 12 - 350K, from the far-infrared to the near-infrared (~ 40 - 10,000cm ⁻¹). The overall experimental uncertainty in the reflectance data does not exceed ±0.5%.