Structural and Thermo-Physical Properties of 3C-SiC: High-Temperature and High-Pressure Effects

Based on the density functional theory (DFT), a systematic theoretical investigation on the structural parameters and finite temperature thermo-physical properties of cubic silicon carbide (3C-SiC) is reported. Our results regarding the structural parameters, melting point, Knoop micro hardness, and thermal conductivity show generally satisfactory accord with experiment and other calculated findings of the present literature. The material of interest is predicted to transform from the zinc-blende (B3) phase to the rock-salt phase (B1) at a pressure of around 70 GPa, which corresponds to a volume collapse of around 18.1%. This agrees well with several experimental and previous theoretical data. Based on the Debye model, the thermo-physical properties at temperatures up to 2000 K and for pressures up to 70 GPa are analyzed and discussed. The authors' results show a monotonous change of the thermo-physical properties of the material in question against temperature or pressure. This accords well with the general trend commonly reported in the present literature.