Structural Stability of the Metastable Solid Solution in the Equilibrium Immiscible Ag–Mo System Predicted by an ab Initio Derived Potential

Abstract

Based on the cohesive energies and lattice constants of a few possible non-equilibrium Ag–Mo compounds obtained by ab initio calculation, a Finnis–Sinclair (FS) potential of the equilibrium immiscible Ag–Mo system is derived. Applying the proven realistic potential, molecular dynamics simulation is carried out to study, at an atomic scale, the structural stability of the Ag-based solid solutions. The simulation results predict that the fcc crystalline structure can be preserved until the Mo concentration reaches 13 at.% and the correlation of the lattice constant of the Ag-based solid solutions vs the Mo concentration is in good agreement with Vegard’s Law. In addition, the heats of formation of the fcc Ag–Mo solid solutions calculated by the derived potential are quite agreeable with that calculated by Miedema’s theory.