Trilayer media for high track density longitudinal recording

Abstract

This paper introduces a new recording method using a trilayer medium (recording layer/nonmagnetic layer/soft magnetic layer/substrate) to diminish the side written band width (ΔW). Magnetostatic coupling between the soft magnetic layer in the media and the write head poles decreases the side fringing field off the track edges. Off-track overwrite experiments revealed that the trilayer media reduced ΔW by 40%–60% compared to the monolayer medium while maintaining the effective write track width and the linear resolution.

FeAl underlayers for CoCrPt thin film longitudinal media

“…Mallary 12 has patented a longitudinal medium which has an improved cross-talk performance by using a magnetic underlayer to suppress off-track fringing signals. Akiyama et al 13 have claimed similar results with a soft-magnetic CoFeTa underlayer. The soft-magnetic underlayer can lead to a narrower side written guard band thereby increasing the track density.…”