Alumina deposition by activated reactive evaporation

Alumina deposits were synthesized at various deposition temperatures from 700 to 1200°C using the activated reactive evaporation process by evaporating aluminum in the presence of a partial pressure of oxygen. The deposits were characterized by X-ray diffraction, scanning electron microscopy and microhardness measurements. The structure is predominantly amorphous at lower deposition temperatures and the equilibrium α-Al₂O₃ at higher deposition temperatures. The results compare closely with those of Al₂O₃ deposits produced by direct evaporation and sputtering.