Structural Stability and the Correlation of Lattice Constant versus Tantalum Concentration of the Ag-Based Fcc Solid Solutions Studied by Molecular Dynamics Simulation

Abstract

Based on the cohesion energies and lattice constants of some Ag–Ta non-equilibrium solid phases obtained by ab initio calculations, an embedded atom method (EAM) potential of the equilibrium immiscible Ag–Ta system was derived. Applied the derived potential, molecular dynamics simulation was carried out to predict, at an atomic scale, the quantitative correlation of the lattice constant of the Ag-based solid solutions versus the Ta concentration. The simulation results predict that the fcc crystalline structure can be preserved in the Ag-based solid solutions until the Ta concentration reaches 10 at.% and that the correlation of the lattice constant of the Ag-based solid solutions versus the Ta concentration is in good agreement with that deduced by Vegard's Law only when the Ta concentration is less than 6 at.%.