A molecular dynamics study was made of Cu solute-atom diffusion in a Fe-0.9at%Cu alloy, using high-temperatures and high-vacancy concentrations to hasten the convergence of the calculation. A value of 0.61eV was found for the migration energy of Cu in the body-centered cubic Fe matrix, in good agreement with available experimental results. The main diffusion mechanisms under the conditions simulated were identified, and the effect of vacancy and solute clustering on Cu migration was assessed. In addition, a rigorous computation of the solute enhancement factor, correlation factor and solute diffusivity was performed within the five-frequency theoretical framework and the harmonic approximation.

Cu Diffusion in α-Fe: Determination of Solute Diffusivities using Atomic-Scale Simulations. Marian, J., Wirth, B.D., Odette, G.R., Perlado J.M.: Computational Materials Science, 2004, 31[3-4], 347-67