Study on density and lattice compression of Al, Cu and AlCu in high temperature and pressure from statistical moment method

Abstract

We derive analytic expressions of Helmholtz free energy, crystal parameters, nearest neighbor distance and mean nearest neighbor distance between two atoms, volume and equation of state of metal and substitutional alloy with FCC structure on the basis of the statistical moment method. We perform numerical calculations of density and ratio of volume at pressure [Formula: see text] to volume at zero pressure for metals Al, Cu and substitutional alloy AlCu at temperature up to 1500 K and pressure up to 350 GPa when using the Mie–Lennard–Jones [Formula: see text] potential and the coordination sphere method. Our calculation results are compared with the experimental data, other theoretical calculations and molecular dynamics simulations.