Suppression of Spike Noise from FeCSi Film for Backlayer of Double-Layered Perpendicular Magnetic Recording Medium

Abstract

The relationships among magnetic properties, noise characteristics, and structures of FeCSi laminated films developed as soft magnetic backlayers of double-layered perpendicular magnetic recording media were examined to find a way to suppress spike noise. FeCSi laminated films were fabricated by alternately stacking soft magnetic layers with non-magnetic intermediate layers. The periods of the cross-tie walls in FeCSi monolayers lengthened as the film thickness decreased. The periods of the cross-tie walls in the laminated films were longer than those in the monolayers. This indicated that the lamination technique was effective in preventing free poles from forming on the surface of the laminated films and that amplitudes of spike noise from the laminated films should have been suppressed. By using FeCSi soft magnetic layers with a thickness of 20 nm and carbon intermediate layers with a thickness of 5 nm, amplitudes of spike noise from the laminated films were suppressed sufficiently for practical use. The laminated films had a high saturation magnetization of 1.6 T and low media noise that was on the same level as in conventional longitudinal magnetic recording media.