Formation of amorphous Al-transition metal (TM: Fe, Co, Ni) binary alloy films by RF-sputtering

Abstract

A new type AlTM amorphous alloy was produced by RF-sputtering under Ar atmosphere. The existence of the amorphous phase was confirmed by X-ray diffraction, transmission electron microscopy, calorimetric and electrical resistivity measurements. It was found that the amorphous phase is formed in the limited composition range of about 75 to 90 at.% Al and the formation of the amorphous phase in such a limited composition range is closely associated with the existence of several intermetallic compounds (Fe 4Al 13, FeAl 6, Co 4Al 13, Co 2Al 9, NiAl 3) in nearly the same composition range having a crystallographically complex structure. The crystallization temperatures of the amorphous alloys are 360°C, 260°C and 220°C for AlFe, AlCo and AlNi alloys, respectively.