The results of molecular dynamics simulations of the diffusion of self-interstitial atom clusters in Fe-Cr alloys with various Cr contents were presented. It was shown that, with increasing Cr concentration, the cluster diffusivity first decreased and then increased, in accordance with the predictions of a model based upon molecular static calculations. The minimum diffusivity was found at about 10at%Cr for small clusters, and shifted towards lower concentrations with increasing cluster size. The migration energy of self-interstitial atom clusters was found to lie between the binding energy of a Cr atom with a crowdion, and half of it. This indicated that the mechanism of cluster migration involved the movement of individual crowdions from one Cr atom to another. The values which were obtained statically were much higher and were argued to be more reliable, due to the better sampling of different configurations within a larger simulation box.

Modelling the Diffusion of Self-Interstitial Atom Clusters in Fe-Cr Alloys. D.Terentyev, L.Malerba, A.V.Barashev: Philosophical Magazine, 2008, 88[1], 21-9