The thermal conductivity of polycrystalline YBaℓCuℓOℓ superconductor from 10 K to 300 K

Author

Jeffery Michael Schmitz

Date of Award

12-1994

Degree Type

Thesis

Degree Name

Master of Science

Major

Physics

Major Professor

James R. Thompson

Committee Members

Brooks, Canright

Abstract

The steady-state longitudinal heat flow method was used to determine the thermal conductivity of polycrystalline, bulk YBa₂Cu₄O₈ over the temperature range of 10 to 300 K. YBa₂Cu₄O₈is an oxide material that exhibits superconducting properties (loss of electrical resistance and partial or complete expulsion of magnetic fields) at temperatures lower than 80 K. The measurement of thermal conductivity, γ, for this material proved to be difficult because of the physical limitations of sample size and the low thermal conductivity of the material. The electrical resistivity and thermal conductivity of YBa₂Cu₄O₈were determined and used to infer the behavior of electrons and phonons in the material.

Existing theory cannot explain some features of the experimential results. At temperature, T, below 40 K, the dependence of γ on T was relatively weak, with γ α 1; in contrast, existing theory predicts a stronger dependence, with γ α Τ₃. This result was compared to a similar material,YBa₂Cu₃O_7-x, and a similar dependence was found.

Recommended Citation

Schmitz, Jeffery Michael, "The thermal conductivity of polycrystalline YBaℓCuℓOℓ superconductor from 10 K to 300 K. " Master's Thesis, University of Tennessee, 1994.
https://trace.tennessee.edu/utk_gradthes/11672