Transport Properties and the Entropy-Scaling Law for Liquid Tantalum and Molybdenum under High Pressure

Abstract

Molecular dynamics simulations are applied to study the transport properties, including the self-diffusion coefficient and viscosity, of liquid tantalum and molybdenum under high pressure conditions. The temperature dependence of self-diffusion coefficient, viscosity and the pair correlation entropy under high pressure conditions are investigated. Our results show that the Arrhenius law well describes the temperature dependence of self-diffusion coefficients and viscosity under high pressure, and the diffusion activation energy decreases with increasing pressure, while the viscosity activation energy increases with increasing pressure. The temperature dependence of the pair correlation entropy is well described by 1/T scaling. Furthermore, we find that the entropy-scaling laws, proposed by Rosenfeld for self-diffusion coefficients and viscosity in simple liquids under ambient pressure, still hold well for liquid tantalum and molybdenum under high pressure conditions.