It was recalled that molecular dynamics simulations of displacement cascades had long revealed that glissile clusters of self-interstitial crowdions formed directly in cascades and migrated 1-dimensionally along close-packed directions, with extremely low activation energies. Under various conditions, a crowdion cluster could change its Burgers vector and glide along a different close-packed direction. A recently developed production bias model of microstructure evolution under irradiation was specifically structured so as to take account of the unique properties of the vacancy and interstitial clusters produced in the cascades. Atomic-scale kinetic Monte Carlo simulations had also played a useful role in understanding the defect reaction kinetics of 1-dimensionally migrating crowdion clusters as a function of the frequency of direction changes. This had made it possible to incorporate the migration properties of crowdion clusters, and changes in reaction kinetics, into the production bias model. Similar kinetic Monte Carlo simulations were used here in order to investigate the important role that crowdion clusters could play in the formation and stability of void lattices. The creation of stable void lattices, starting from a random distribution of voids, was simulated by using a kinetic Monte Carlo model in which vacancies migrated 3-dimensionally and self-interstitial atom clusters migrated 1-dimensionally; interrupted by directional changes. A need for both 1-dimensional migration and Burgers vectors changes of self-interstitial atom clusters, for the production of stable void lattices, was demonstrated and the effects of the frequency of Burgers vector changes were described.

Kinetic Monte Carlo Simulations of Void Lattice Formation during Irradiation. H.L.Heinisch, B.N.Singh: Philosophical Magazine, 2003, 83[31], 3661-76