Formation mechanism of the di-vacancy in FCC metal Pt

Abstract

The formation mechanism of the di-vacancy in FCC metal Pt has been studied from the migration of the two vacancies by using the modified analytical embedded atom method (MAEAM). The lattice relaxation resulted from the existence of the vacancies is performed with the molecular dynamics (MD) method. For migration of an isolated vacancy in Pt, the favorable path is the first-nearest-neighbor (1NN) migration. From the minimum formation energy or the maximum binding energy of the di-vacancy, we know that the 1NN configuration of the di-vacancy is the most stable. Up to the fifth-nearest-neighbor (5NN) configuration of the di-vacancy, the migration of the two vacancies is always to approach each other in the shortest paths of 5NN→2NN→1NN, 4NN→1NN, 3NN→1NN and 2NN→1NN.