Structure and properties of reactively-sputtered AlxCoCrCuFeNi oxide films

Abstract Hex-element Al x CoCrCuFeNi ( x = 0.5, 1, 2) metallic and oxide films were deposited by sputtering homogeneous alloy targets in argon and argon–oxygen plasma, respectively. The metallic films are primarily composed of simple face-centered and/or body-centered cubic phases, while the oxide films comprise only a cubic-spinel crystalline phase. The aluminum content plays an important role in the structure and properties of both the metallic and the oxide Al x CoCrCuFeNi films. The lattice constant increases for both the face-centered and the body-centered cubic metallic phases while it decreases linearly for the spinel phase with increasing x value. The oxide films are nanocomposite in nature and their film hardness is enhanced by both aluminum and oxygen content with the highest hardness of 22.6 ± 1.6 GPa being achieved in this series of films.