THE ELECTRONIC CONTRIBUTION TO THE THERMAL-CONDUCTIVITY OF LAYERED HIGH-T-C MATERIALS

We have used the variational approach to calculate the in-plane electr onic thermal conductivity of high-T-c superconductors along the lines of a two-fluid model. To account for the layered structure of these co mpounds, an anisotropic electronic energy spectrum with a Josephson-li ke coupling between the superconducting planes within a Lawrence-Donia ch model has been assumed. Both elastic and inelastic electronic scatt ering processes are considered. The theoretical results obtained are i n quantitative agreement with experimental data on Bi2Sr2CaCu2O8 singl e crystals and Bi2Sr2Ca2Cu3O10 polycrystals. These results suggest an electronic origin of the peak observed in the thermal conductivity of these materials.