Atomic-scale computer simulation was used to study the interaction between a vacancy and a cluster of self-interstitial atoms in metals with hexagonal close-packed, face-centred cubic or body-centred cubic crystal structures: α-Zr, Cu and α-Fe. The effects of cluster size, atomic structure, dislocation nature of the cluster side and temperature were investigated. A vacancy could recombine with any interstitial in small clusters and this did not affect cluster mobility. With increasing size, the clusters developed a dislocation character and their interaction with vacancies depended upon whether the cluster sides dissociated into partial dislocations. A vacancy recombined only on undissociated sides and corners created with undissociated segments. Vacancies within the cluster perimeter did not recombine, but restricted cluster mobility. The temperature enhanced recombination by either increasing the number of recombination sites or assisting vacancy diffusion towards such sites. The results were considered with regard to differences in the irradiation microstructure evolution of body-centred cubic, face-centred cubic and hexagonal close-packed metals and higher-level theoretical modelling techniques.

On the Interaction between a Vacancy and Self-Interstitial Atom Clusters in Metals. M.A.Puigví, N.de Diego, A.Serra, Y.N.Osetsky, D.J.Bacon: Philosophical Magazine, 2007, 87[23], 3501-17