High density recording on CoSm/Cr thin film media

Abstract

Current research activities in high density longitudinal magnetic recording media are concerned with reducing medium noise and transition width. To lower the medium noise it is necessary to obtain thin films with magnetically non-interacting grains a few nm in size, and to minimize the transition width, a thin medium possessing a high coercivity is essential. A previous study reported that coercivities >2400 Oe could be obtained for 14 nm thick CoSm films grown on a Cr underlayer. Since that time coercitivities approaching 3000 Oe have been attained. We report here the recording results for high coercivity CoSm/Cr hard disks fabricated on glass substrates. The recording results were obtained at a flying height of 7.5 μin using a thin film inductive head which had 9 turns, 0.58 μm gap length and 28 μm pole tip width.