Molecular Dynamics Simulations of the Elastic Anisotropy of Pd at Extreme Conditions**Supported by the National Natural Science Foundation of China (41574076), the Basic Research of Technology Program of China under Grant No. JSHS2014404B002, the Young Core Teacher Scheme of Henan Province under Grant No. 2014GGJS-108, and key project of science and technology research of Henan Provincial Education Department under Grant

Abstract

It is very interesting to discover the elastic properties of engineering material palladium, especially its elastic anisotropy along Hugoniot states. We here investigate the evolution of its high pressure and temperature (PT) elastic ansotropy along Hugoniot using molecular dynamics simulations based on accurate classical interatomic potential. In order to testify the validity of the interatomic potential of Pd in describing the high PT elastic properties, we calculate its isothermal and adiabatic elastic moduli using molecular dynamics method. The obtained data are in good agreement with experimental data. From the isothermal elastic constants, we deduce the Hugoniot acoustic velocities and find that the resulting data are in good agreement with experimental acoustic velocity data. Based on the reliable elastic constants, we further investigate the spacial elastic ansotropy along Hugoniot PT states. It is found that the spacial elastic anisotropy of Pd increases along Hugoniot states.