Calculation of Thermodynamic Properties for B2-YCu Intermetallics with Molecular Dynamics

Abstract

The thermodynamic properties of YCu intermetallics with B2 structure are investigated with molecular dynamics. The thermodynamic properties at various temperatures, such as lattice parameter, cohesive energy, enthalpy of formation, elastic constants, heat capacity, vibrational entropy and vibrational free energy are computed. The present calculated results show good agreements with available experimental and previous calculated data. The calculated elastic constants suggested that YCu compound has a mostly ductile behavior. This prediction match well with experimental findings. At high temperature, the heat capacity tends to a constant with obeys the classical equipartition law. At 300K, the heat capacity of YCu is 23.80J mol-1 K-1. The calculated coefficient of thermal volume expansion α increases sharply at T<20K. When T<300K α gradually approaches a linear increase with enhanced temperature and the propensity of increment becomes moderate. At T=300K, the value of α is 5.88×10-5K-1. And those data enrich thermodynamic data-base for YCu compound.