Computer experiment on the electron-irradiation-induced crystalline-amorphous transition

Abstract

By introducing vacancy-interstitial pairs, both f.c.c. and b.c.c. model crystals constructed by computer have been transformed to an amorphous structure in accordance with electron-irradiation experiments. The crystalline-amorphous (C-A) transition occurs only gradually, without being affected by the presence of an amorphous nucleus and is completed at 0·6 to 1·0 displacement per atom, much larger than the experimental estimates. These results suggest that the apparently sharp C-A transition which is experimentally observed is brought about by an accelerated damage rate accompanying disordering, rather than by an ordinary nucleation and growth process of a new phase. The tendency towards amorphization is discussed in terms of disordering energy.