Magneto-Optical Properties in Ultrathin Co/Pd and Co/Pt Multilayer Films

Abstract

Co/Pd and Co/Pt multilayer films were prepared by magnetron-type sputtering and their magnetic properties were characterized by a polar Kerr loop tracer. Both multilayer films had perpendicular magnetic anisotropy when the Co layer became ≦10 Å. It was found that the magneto-optical and magnetic properties were significantly affected by the film thickness. The Kerr rotation angle θ_k was enhanced at the film thickness t\lesssim500 Å and the Kerr remanence to saturation ratio became θ_kr/θ_k=1 at t≦200 Å. In the Co/Pd system, the coercive force was influenced by the sputtering gas pressure. Simultaneous enhancement in θ_k and θ_kr/θ_k is assumed to originate from the different natures.