Antisite Defects of the L1₂ Structure Determined by the Phase Field Microelasticity Model

A phase field microelasticity simulation is performed to examine the antisite defect of L1₂-Ni₃Al in Ni₇₅Al_5.3V_19.7 ternary alloy. Combinimg strain energy with the phase field model leads to an atom configuration change as time proceeds. For the Ni sublattice, the antisite defect Al_Ni, the equilibrium occupancy probability (OP) of which declines, precedes Ni_Ni and V_Ni in reaching equilibrium; subsequently, Ni_Ni and V_Ni present a phenomenon of symmetrical rise and decline individually. Similarly, for the Al sublattice, the antisite defect Ni_Al, the OP of which eventually rises, takes fewer time steps than Al_Al and V_Al to attain equilibrium. Thereafter, Al_Al rises while V_Al declines symmetrically at the axes of the Ni_Al curve. Furthermore, the OP for the Al sublattice is much more sensitive to strain energy than that for the Ni sublattice.