A microstructural study of some amorphous transition metal-metalloid surface alloys formed by ion implantation

Abstract
Recent work has suggested that non-crystalline surface layer alloys can be formed in certain metals by ion implantation at large doses. The mechanism responsible for the ‘amorphization’ is thought to involve the concept of the energy spike in the displacement cascade. This paper describes some structural investigations of iron, cobalt and nickel foils implanted with metalloid, inert gas and self ions at doses approaching saturation. The results of this study, and those of previous work, suggest that only certain ion-metal combinations form such layers. The atomic arrangements and crystallization phenomena in the non-crystalline layers formed here are compared with those in similar alloys formed by deposition and liquid quenching techniques. Finally, the metastability of the alloys is discussed in terms of factors that are thought to promote non-crystalline structures.