Structure stabilities and mono-vacancy properties of BCC transition metals by MAEAM potentials

Abstract

The structure stabilities and the mono-vacancy properties of the body-centered cubic transition metals were studied by the molecular static or molecular dynamic method on the basis of the improved ones of the modified analytic embedded atom method potentials. First, the molecular static method was applied to calculate the cohesive energies for the several possible structures under the assumption of the constant volume and to study the structure energies as functions of the volume, the formation and migration energies of the mono-vacancies for the body-centered cubic transition metals, Cr, Fe, Mo, Nb, Ta, V and W. Second, we derived the formulae to calculate the forces acting on the atoms on the basis of the modified analytic embedded atom potential form for the body-centered cubic and the face-centered cubic metals. These formulae were applied to simulate the structure stabilities and the mono-vacancy relaxation properties for the body-centered cubic transition metals by the molecular dynamic method. The molecular static and the molecular dynamic simulation results are in good agreement with the experimental data and the precedent results. Thus, it can be seen that the improved potential models and the formulae are effective for the researches on the properties of the body-centered cubic transition metals.