Thermal conductivity of single-crystal Bi-Sr-Ca-Cu-O

The ab-plane thermal conductivity κ of single-crystal ${\mathrm{Bi}}_2$ ${\mathrm{Sr}}_2$ ${\mathrm{CaCu}}_2$ ${\mathrm{O}}_{8\mathrm{-}\mathit{x}}$ has been measured from 25 to 300 K, for samples of varying oxygen configuration. Complementary electrical-conductivity measurements on the same crystals allow κ to be accurately decomposed into electronic and phonon contributions. For metallic samples the electronic contribution to κ is substantial. Analysis of κ in the normal and superconducting states allows the defect-scattering and electron-scattering contributions to ${\mathrm{\kappa }}_{\mathrm{phonon}}$ to be evaluated near ${\mathit{T}}_{\mathit{c}}$. κ in the superconducting state is consistent with a BCS description.