Ambipolar Diffusion Contribution to High‐Temperature Thermal Conductivity of Titanium Carbide

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Abstract
The odd thermal conductivity behavior of transition metal carbides–Kincreasing with increasingT–has been interpreted as resulting from the strong scattering of electrons by carbon vacancies and polar optical phonons and from the strong scattering of phonons by vacancies and conduction electrons. These scattering processes have been used in a Callaway analysis to fit the thermal conductivity of TiC from the liquid He temperature to 1000 K; however, at the highest temperatures a residual contribution toKwas noted which increased with increasingT.An analysis of the Lorenz function has indicated that this contribution is electronic. The present work indicates, using a theory modified for semimetals, that the additional conductivity may be ambipolar diffusion (electron‐hole migration and recombination).