Thermal conductivity and superconductivity in EuBa2Cu3O7-x

Abstract

We have measured the thermal conductivity κ from 2 to 200 K in the superconducting ceramic EuBa2Cu3O7−x observing an anomaly at the superconducting transition temperature Tc. Using general arguments and approximations, and supposing that the electrical resistivity is due to electron-phonon interaction, we separate quantitatively the different contributions to κ. The "observed" electron-limited phonon conductivity fairly follows the Bardeen-Rickayzen-Tewordt theory and a Bardeen-Cooper-Schrieffer-like energy gap with 2Δ(0)kBTc=3.3±0.7, in agreement with published data from other kinds of measurements.