Fabrication of a Single-Layered Perpendicular Magnetic Recording Medium with a Ge Underlayer

Abstract

Sputter-deposited Ge was applied as an underlayer of a Co-Cr-Pt-Ta single-layered perpendicular magnetic recording medium. It is important to apply a paramagnetic Co-Cr₄₀ intermediate layer to obtain a film that has high perpendicular magnetic anisotropy without Ge diffusion into the magnetic layer. As the Ge underlayer thickness was increased, the magnetic properties and crystalline orientation improved, the media noise power and spectrum form changed, and the noise sources also seemed to change. Application of a thicker underlayer is an effective way of obtaining a high S/N value.