Molecular dynamics simulations of lattice thermal conductivity of bismuth telluride using two-body interatomic potentials

Abstract

Two-body interatomic potentials in the Morse potential form have been developed for bismuth telluride, and the potentials are used in molecular dynamics simulations to predict the thermal conductivity. The density-functional theory with local-density approximations is first used to calculate the total energies for many artificially distorted ${\text{Bi}}_{2}{\text{Te}}_{3}$ configurations to produce the energy surface. Then by fitting to this energy surface and other experimental data, the Morse potential form is parameterized. The fitted empirical interatomic potentials are shown to reproduce the elastic and phonon data well. Molecular dynamics simulations are then performed to predict the thermal conductivity of bulk ${\text{Bi}}_{2}{\text{Te}}_{3}$ at different temperatures, and the results agree with experimental data well.