Preparation and Properties of (CoFe₂O₄)-(Co-CoO) Composite Films for Perpendicular Magnetic Recording

Abstract

Cobalt ferrite films with perpendicular magnetic anisotropy were prepared by facing-targets sputtering, and their magnetic properties and structure were investigated. A film deposited at P_o2=0 mTorr and post-annealed at 300°C had H_c⊥ = 1.5 kOe, H_cr=3.5, and S_q⊥=0.46. The film deposited at P_o2=0 mTorr and post-annealed at 300°C had outstanding squareness ratio (S_q⊥) compared with that of a CoFe₂O₄ single-phase film. When the binding energies of the Co_2p and Fe_2p electrons of the film were measured by XPS, the film was found to be made up of a (CoFe₂O₄)-(Co-CoO) composite.