Molecular statics and dynamics studies were made of self-interstitial diffusion mechanisms in various model structures by using embedded-atom method interatomic potentials. The simulations were carried out, at constant energy and volume, for various temperatures. Defect diffusion coefficients were estimated, and migration jumps at low and relatively high temperatures were identified qualitatively by means of simple visualization techniques. A relevance of crowdion-type interstitials was demonstrated in the case of the hexagonal close-packed and body-centered cubic structures. Highly non-Arrhenius behavior was predicted for basal diffusion in Zr. The dynamically computed migration energies yielded magnitudes which were roughly half of those which were computed by using static techniques. It was concluded that this was due to the difficulty of directly applying transition-state theory under conditions which involved moderately complex defect and/or energy-barrier structures.

Computer Simulation of SIA Migration in BCC and HCP Metals. R.C.Pasianot, A.M.Monti, G.Simonelli, E.J.Savino: Journal of Nuclear Materials, 2000, 276, 230-4