Monte Carlo calculations of Cu atom diffusion via the vacancy mechanism in bcc Fe were presented. The activation energy of atomic jumps was taken from recent ab initio calculations. It was shown that the vacancy–Cu atom cross-diffusion coefficient was positive at all temperatures, for which the body-centered cubic crystal structure was preserved. This was shown to be opposite to the description obtained using data calculated with an empirical interatomic potential for the Fe–Cu system. The sensitivity of the results to the values of the activation energy within the uncertainty of ab initio calculations was analyzed. Implications of the results for the features of Cu precipitation in ferritic steels under neutron irradiation were analyzed.

Monte Carlo Modelling of Cu Atom Diffusion in α-Fe via the Vacancy Mechanism. A.V.Barashev, A.C.Arokiam: Philosophical Magazine Letters, 2006, 86[5], 321-32