Thermal Conductivity of Transition Metal Carbides

Previous measurements of the thermal conductivity of TiC, ZrC, and NbC by the present authors showed that at low temperatures the phonon‐electron scattering in these materials is strong and gives rise to an unusual temperature dependence of the lattice thermal conductivity. The Callaway analysis of those data is now extended to include the high‐temperature data of Taylor for TiC. The analysis of the thermal conductivity of TiC from 2° to 2000°K indicates that: (1) For samples with higher carbon contents, it is necessary to modify the phonon‐electron relaxation rate at low temperatures and (2) a strong point‐defect scattering term is required to explain the high‐temperature data. This scattering is due primarily to force‐constant changes rather than mass changes which are introduced by the presence of vacancies.