First-principles study of solute diffusion in Ni_3Al

Using first-principles calculations in combination with Wagner-Schottky and kinetic Monte Carlo methods, the diffusion behaviors of solutes via various vacancy-mediated diffusion mechanisms in L1₂ γ'-Ni₃Al were investigated. The formation energies of the point defects and the migration energies for solutes were calculated. Adding alloying elements can decrease the defect-formation energies of Ni_{m Al}, increase the defect-formation energies of Al_Ni, and have little effect on the formation energy of V_Ni. The migration energies of solutes are related with the site preference and the diffusion mechanism. The diffusion coefficients of Ni, Al, and solutes were calculated, and the concentration of antisite defects plays a crucial role in the elemental diffusion.