Calculation of Thermodynamic and Thermoelastic Properties for Ductile B2-YAg Intermetallics with Molecular Dynamics

Abstract

The thermodynamic and thermo-elastic properties of ductile intermetallic compounds YAg with B2 structure are investigate with molecular dynamics. The thermodynamic properties at various temperatures, such as lattice parameter, cohesive energy, enthalpy of formation, heat capacity, vibrational entropy and vibrational free energy are computed. The present calculated results show good agreements with available experimental and previous calculated data. At high temperature, the heat capacity tends to a constant with obeys the classical equipartition law. At 300K, the heat capacity of YAg is 23.91 J mol-1 K-1. And those data enrich thermodynamic data-base for YAg. At the whole range 0-600K, the elastic constants follow a normal behavior with temperature that those decrease with increasing temperature, and satisfy the stability conditions for YAg compound. The Cauchy pressure and B/G for YAg increase with elevating temperature. Our results mean that increasing temperature may improve ductility of YAg.