Properties of mono-vacancy in L12-type Ni3Al ordered alloy

The relaxed structures and the formation and migration energies of the mono-vacancy in L1₂-type Ni₃Al ordered alloy have been investigated by combining the modified analytical embedded-atom method (MAEAM) with molecular dynamics (MD) simulation. The movements of the atoms in the vicinity of the mono-vacancy are toward the vacancy, except for the second-nearest-neighbor Al atoms and the fifth-nearest-neighbor Ni atoms around an Al vacancy and the third-nearest-neighbor Al atoms and the fourth-nearest-neighbor Ni atoms around a Ni vacancy that move outward from the vacancy. Furthermore, each of the atoms in the vicinity of either an Al or a Ni vacancy moves approximately along a line connected between the atom and the vacancy. From energy minimization, it is easy for a Ni vacancy to form and to migrate in one nearest-neighbor jump.