Thermal properties of GeTe simulated by molecular dynamics
Keywords:Molecular dynamics, GeTe, Thermal conductivity, Heat capacity, Lattice parameter
The thermal properties of GeTe were simulated by molecular dynamics (MD) method in temperature range 300 K − 700 K and the pressure range 1 MPa − 1.5 GPa. The cluster atomic based on rocksalt structure used Ge 256 atoms and Te 256 atoms in dimension 4×4×4 unit cells. The interatomic interaction used the Morse-type potential functions and the Busing-Ida type potential. Then the potential parameters were determined by fitting calculated lattice constant to agree with the literature at room temperature. The compressibility and linear thermal expansion coefficient were analyzed and contribution to analysis heat capacity. The thermal conductivity was analyzed by the heat flux autocorrelation function. It was found that, the heat capacity of GeTe was increased with increasing temperature agree with the Dulong-Petit law about 97.92 J K-1 mol-1 at 300 K. The thermal conductivity was decreased with increasing the temperature about 1.97 W m-1 K-1 to 1.09 W m-1 K-1 at 300 – 700 K.