Surface physics, thin films

SiC thermal conductivity: calculation of the isotope effect from first principles

D. A. Chernodubov, A. V. Inyushkin

National Research Centre "Kurchatov Institute", Moscow, Russia

Abstract: The thermal conductivity temperature dependence $\kappa(T)$ of a hexagonal 2$H$-SiC silicon carbide crystal was calculated using the first-principle approach for the orientation of the heat flux in the basal plane and along the hexagonal axis c in the temperature range from 100 to 500 K. The effect of silicon and carbon isotopic disorder on thermal conductivity is considered. It was found that, at a temperature of 300 K, the thermal conductivity of isotopically pure 2$H$-SiC containing 100% $^{28}$Si and 100% $^{12}$C is higher by 15.2% and 12.4% for directions along and across the basal plane, respectively, than that of crystals with a natural composition of silicon and carbon isotopes. For crystals with a natural mixture of carbon isotopes $^{\text{nat}}$C, the isotope effect for silicon is 14.5% and 11.9% for these directions.

Keywords: single crystal, thermal conductivity, silicon carbide, first principle calculation.

Received: 14.04.2023
Revised: 14.04.2023
Accepted: 06.05.2023

DOI: 10.21883/FTT.2023.06.55669.62

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