The gadolinium sputtering target is a composed of high-purity metal europium (Gd). It has a melting point of 1312°C, a boiling point of 3250°C, and a density of 7.895g/cm3. Gadolinium is a silvery-white metal when oxidation is removed. It is only slightly malleable and is a ductile rare-earth element. Gadolinium reacts with atmospheric oxygen or moisture slowly to form a black coating.