Simulated Equations of State of ZnO with Rocksalt Phase at High Temperature and High Pressure

Abstract

The equation of state of ZnO with rocksalt phase under high pressure and high temperature was calculated by using the molecular dynamics method with effective pair potentials which consist of the Coulomb, dispersion, and repulsion interaction. It was shown that molecular dynamics simulation is very successful in accurately reproducing the measured molar volumes of the rocksalt phase of ZnO over a wide range of temperatures and pressures. The simulated P-V-T data matched experimental results up to 10.4 GPa and 1273 K. In addition, the linear thermal expansion coefficient, isothermal bulk modulus and its pressure derivative were also calculated and compared with available experimental data and the latest theoretical results at ambient condition. At extended temperature and pressure ranges, the P-V-T relationship, linear thermal expansion coefficient, and isothermal bulk modulus were predicted up to 2273 K and 50 GPa. The detailed knowledge of thermodynamic behavior and equations of state at extreme conditions are of fundamental importance to the understanding of the physical properties of ZnO.