Low-temperature fabrication of an epitaxial alumina thin film on a ferromagnetic metal layer

Abstract

We fabricated an epitaxial Al₂O₃/Ni bilayer film on a sapphire substrate using PLD process and selective hydrogen reduction method. The epitaxial Al₂O₃/NiO bilayer film was firstly fabricated by PLD process in low temperatures. Then, the fabricated Al₂O₃/NiO film was annealed in hydrogen atmosphere, and only the NiO layer was reduced to Ni metal layer. As the results, the epitaxial Al₂O₃/Ni (insulator/metal structure) film was obtained. The fabricated epitaxial Al₂O₃/Ni bilayer film exhibited a very smooth surface.