DEPOSITION OF HIGHLY SUPERSATURATED METASTABLE ALUMINUM-MOLYBDENUM ALLOYS BY CLOSED FIELD UNBALANCED MAGNETRON SPUTTERING

Aluminium-molybdenum alloys, over the complete binary alloy compositio nal range, have been produced at low pressure (0.8 Pa) and low tempera ture (< 400K) by simultaneous co-sputtering from two 75mm diameter tar gets mounted on two closed field unbalanced magnetrons. Highly-supersa turated, single-phase solid solutions over the ranges 0 - 11% molybden um and 55 - 100% molybdenum have been obtained. In the approximate ran ge 30 - 55% molybdenum, single phase amorphous or micro-crystalline gl ass-like alloys, having a fully dense appearance are formed. The phase s existing at intermediate compositions, in the range 11 - 30% molybde num, are mixtures of the glass-like phase and the aluminium-rich solid solution. No intermediate region between the molybdenum rich solid so lution zone and the glass-like zone has been observed and only traces of the equilibrium intermetallic AI,Mo, have been formed at a composit ion of 58% molybdenum.