Atomistic modeling of finite-temperature properties of β-SiC. I. Lattice vibrations, heat capacity, and thermal expansion

We present a two-part theoretical study of the thermal properties of crystalline β-SiC based on an empirical interatomic potential developed by Tersoff which emphasizes the bond-order nature of covalent solids. In part I we use this description of interatomic interactions in both lattice dynamical calculations and molecular dynamics simulations with a temperature-scaling procedure to obtain reasonably accurate predictions of the heat capacity and the thermal expansion coefficient. Our results notwithstanding, improvement of the potential to include ionic interactions for the description of vibrational properties, and extension of short-range forces beyond the nearest neighbors, would be quite useful. (orig.)