Interaction of a single interstitial atom with small clusters of self interstitials in α-Fe

The interaction of a self-interstitial atom (SIA) with small clusters (7 and 19 SIAs) in α-Fe has been studied by atomic computer simulation using an interatomic potential of EAM type derived by Ackland et al. Metastable configurations have been investigated by annealing the system at 50 K and 100 K. The interstitial exhibits six non-equivalent configurations that lead to different behaviour under the stress field of the cluster. Special configurations, formed when the SIA joins the cluster, that prevent cluster motion are described. The region where the interstitial is attracted to and joins the cluster and the binding energy map are presented. The capture distance and recombination energy of a vacancy interacting with the same clusters, calculated with the same potential, is given for comparison.