Effects of 1MeV electron irradiation upon Xe precipitates that had been formed by ion implantation, were observed in situ by means of high-voltage transmission electron microscopy. It was found that individual Xe precipitates underwent melting and recrystallization, and migration leading to coalescence and shape changes. These processes were driven by the production of defects without either cascade defect-production or the introduction of additional Xe atoms. The precipitate migration was due to an irradiation-induced surface diffusion process at the Xe/Al interfaces. The coalescence of close precipitates was enhanced by directed motion, as a result of the net displacement of Al atoms out of the volume between them.

Migration and Coalescence of Xe Nanoprecipitates in Al Induced by Electron Irradiation at 300K. C.W.Allen, R.C.Birtcher, S.E.Donnelly, K.Furuya, N.Ishikawa, M.Song: Applied Physics Letters, 1999, 74[18], 2611-3