Amorphous Zr-Cu thin-film alloys with metallic glass behavior

Abstract Binary Zr–Cu thin-film alloys were prepared by non-reactive conventional dc and impulse magnetron co-sputtering using two unbalanced magnetrons equipped with Zr and Cu targets. The magnetron with the Zr target was operated in a dc regime while the magnetron with the Cu target in a pulse regime either at low or high density discharge conditions. The elemental composition in the films was controlled in a very wide composition range (∼10–90 at.%). The evolution of the structure, thermal behavior, mechanical, electrical and surface properties of Zr–Cu films with increasing Cu content was systematically investigated. We found that Zr–Cu thin-film metallic glasses were prepared with the Cu content between approximately 30 and 65 at.% Cu independently of the low or high density discharge conditions used. A clear correlation between the evolution of the crystallization temperature and mechanical properties with increasing Cu content was observed. The deposition at the high density discharge conditions resulted in a preparation of the Zr–Cu thin-film metallic alloys with a compressive stress ( 7 GPa), very smooth (surface roughness  100°) surface.