Amorphization of Fe/Al: Bulk and thin-film effects

The amorphous non-equilibrium state of the system Fe/Al is studied in bulk and thin-film systems. For bulk samples prepared by ion-beam mixing of laser-deposited multilayers, a bcc solid solution is found
for alloys with up to 70 at.% Al. Around 75 at.% Al a Fe2Al5-like crystalline phase is found. An amorphous state with Fe2Al5-like short-range order is found for 80 at.% Al. In thin films, e.g. the amorphous Al-rich transition layer of a laser-deposited Fe/Al multilayer, the amorphous state can exist for
up to 30 at.% Fe due to the high interfacial energy. By ion-beam mixing at low temperatures (about 140 K) an oversaturation of 40 at.% Fe could be achieved.