材料期刊网

The molecular dynamics method has been applied to simulate the melting temperatures of CaF2 at elevated temperature and high pressure and to calculate the P ∼ V equation of state of CaF2 up to 100 GPa at 300 K. The interatomic potential was taken to be the sum of pairwise additive Coulomb, van der Waals attractions, and repulsive interactions. In addition, the shell model was used in molecular dynamics simulation. The pressure dependence of the melting temperature of CaF2 was predicted up to 4 GPa. However, in order to account for the superheating melting of the molecular dynamic simulation, the simulated melting temperatures of CaF2 were corrected by the modem theory of melting. Consequently, the melting temperatures of CaF2 were accurately obtained at elevated temperature and high pressure. Therefore, it is shown that shell-model molecular dynamics simulation at constant pressure indeed provides a useful tool for studying the melting temperatures of other materials under high pressures.