Microscopic Phase-Field Study of the Occupancy Probability of α Sublattices Involving Coordination Environmental Difference for D0₂₂−Ni₃V

The nickel sites of a D0₂₂−Ni₃V phase are subdivided into Ni1 and Ni2 sublattices according to their coordination sphere difference. The occupancy probability (OP) differences influenced by the coordination sphere are interpreted using the microscopic phase field model. The OP of regular atoms (Ni_Ni1, Ni_Ni2), antisite defects (V_Ni1, V_Ni2), and substitutional defects (Al_Ni2, Al_Ni1) have strong site preferences, as well as temperature−dependence features, on both sublattices. These features involve both redistribution of components, and phase transition from D0₂₂ to L1₂.