FORMATION OF AMORPHOUS AL-TRANSITION METAL (TM - FE, CO, NI) BINARY ALLOY-FILMS BY RF-SPUTTERING

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//1//3, FeAl//6, Co//4Al//1//3, 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 degree C, 260 degree C and 220 degree C for Al-Fe, Al-Co and Al-Ni alloys, respectively.