Simulation of Diffusion in FCC NiFe Binary Alloys Using Kinetic Monte Carlo Method

The use of the atomistic kinetic Monte Carlo method was explored to examine the vacancy-mediated diffusion in fcc NiFe binary alloy. Relevant energetic and kinetic parameters were calculated from density functional theory, and these were used to parametrize a pair interaction model for determination of environment-dependent diffusion barriers. Kinetic Monte Carlo simulations were performed to compute the tracer diffusivities as functions of composition and temperature. Calculations for pure Ni and for Ni with dilute amount of Fe yielded results that compare well with experiments. With increasing amount of Fe, the model predicts a slight reduction in the diffusivity of Fe. This trend was examined on the basis of the neighbor pair interactions between atoms.