Head field angle-dependent writing in longitudinal recording

Abstract

Summary form only given. The writing process in magnetic recording is the switching of media grains by the head magnetic field. As the head moves across the media, the grains in the recording layer experience the writing fields that vary both in magnitude and direction. Fundamentally, in the longitudinal recording, the writing field perpendicular component provides a path for the media magnetization gyromagnetic motion. Therefore it is likely to reduce the required longitudinal field for the grain reversal. The traditional Willium-Comstock model includes only the longitudinal components of the head field. It has predicted that the required deep gap field should be roughly 3 times the media (writing) coercivity. This requirement has been contradicted by the recently published experimental result of Liu et al. (see IEEE Trans. Magn., vol. 37, p. 613 et seq., 2001). Using our micro-magnetic recording model, which combines the writing and reading process at head-media level, the impact of the full 3D writing field on the recording process was examined. The present work focused especially on the effect of field angular dependence. A modified Willium-Comstock model was also developed to include the effects of the perpendicular field component. The corrected calculations predicted an optimum writing field that was reduced and agreed reasonably well with the results obtained from experiment and micromagnetic simulations.