Thermal conductivity of $\rm CuGaTe_2$ and $\rm CuInTe_2$ ternary compounds in the temperature range of $300$–$800$ K

The thermal conductivity of $\rm CuGaTe_2$ and $\rm CuInTe_2$ was measured at high temperatures $(300$–$800$ K$)$. The potential mechanisms of heat transport are analyzed. The total thermal conductivity of the examined compounds in the studied temperature range is completely determined by the thermal conductivity of the crystal lattice $\lambda_{\rm lat}$. It is demonstrated that the thermal conductivity of the crystal lattice changes with temperature faster than with $\lambda_{\rm lat} \sim T^{-1}$. The potential causes of the deviation of the thermal conductivity of the crystal lattice from the Eucken law are considered.