Deposition of highly supersaturated metastable aluminium-molybdenum alloys by closed field unbalanced magnetron sputtering

Aluminium-molybdenum alloys, over the complete binary alloy compositional range, have been produced at low pressure (0.8 Pa) and low temperature (< 400K) by simultaneous co-sputtering from two 75mm diameter targets mounted on two closed field unbalanced magnetrons. Highly-supersaturated, single-phase solid solutions over the ranges 0 - 11% molybdenum and 55 - 100% molybdenum have been obtained. In the approximate range 30 - 55% molybdenum, single phase amorphous or micro-crystalline glass-like alloys, having a fully dense appearance are formed. The phases existing at intermediate compositions, in the range 11 - 30% molybdenum, are mixtures of the glass-like phase and the aluminium-rich solid solution. No intermediate region between the molybdenum rich solid solution zone and the glass-like zone has been observed and only traces of the equilibrium intermetallic Al₈Mo₃ have been formed at a composition of 58% molybdenum.