Non-crystallinity of ion-irradiated metals

THE preparation of various metals and metallic alloys in a non-crystalline state using splat cooling, vapour quenching or electrochemical deposition techniques has been reported by many authors. A distinguishing characteristic of such amorphous films is a severe modification of the structure factor from that of the crystalline state. Although usually formed only at low temperatures the non-crystalline state may in some cases be metastable to above room temperature, this being particularly true for alloys near the eutectic. We examine here evidence for metastable non-crystalline alloys resulting from ion irradiation.