Phonon and electron components of the thermal conductivity of tantalum at intermediate temperatures

Abstract

Thermal conductivity, electrical resistivity, and absolute Seebeck-coefficient values for Ta and four Ta-base alloys are reported. The data, which cover the temperature range 80\char22{}400 K, were analyzed to identify the phonon and electron contributions to the thermal conductivity of Ta. Reflecting the strong electron-phonon interaction, the phonon thermal conductivity is rather small and equal to about $\frac{2}{3}$ of the prediction of a theoretical formula. At the highest temperatures investigated, the electronic thermal conductivity and electrical resistivity are consistent with the Sommerfeld-Lorenz number. The electrical resistivity and Seebeck-coefficient results can be satisfactorily fitted to standard theoretical formulas, and these results indicate that deviations from Matthiessen's rule are small and positive.