Modified embedded-atom method interatomic potentials for the Mg-Al alloy system

摘要

We developed new modified embedded-atom method (MEAM) interatomic potentialsfor the Mg-Al alloy system using a first-principles method based on densityfunctional theory (DFT). The materials parameters, such as the cohesive energy,equilibrium atomic volume, and bulk modulus, were used to determine the MEAMparameters. Face-centered cubic, hexagonal close packed, and cubic rock saltstructures were used as the reference structures for Al, Mg, and MgAl,respectively. The applicability of the new MEAM potentials to atomisticsimulations for investigating Mg-Al alloys was demonstrated by performingsimulations on Mg and Al atoms in a variety of geometries. The new MEAMpotentials were used to calculate the adsorption energies of Al and Mg atoms onAl (111) and Mg (0001) surfaces. The formation energies and geometries ofvarious point defects, such as vacancies, interstitial defects andsubstitutional defects, were also calculated. We found that the new MEAMpotentials give a better overall agreement with DFT calculations andexperiments when compared against the previously published MEAM potentials.