Magnetic recording carrier with soft magnetic intermediate layer - below high coercivity layer with perpendicular magnetisation to reduce distortion

摘要

Magnetic recording carrier as described in the parent patent has a magnetic material (I) with anisotropy perpendicular to the recording surface and a relatively high coercivity of ca. 50-400 Oe, recording/play-back taking place by vertical relative movement between the magnetic head and the carrier. Improvement is that there is a layer of soft magnetic material (II), which has a high magnetisation and a magnetisation direction in the plane of the carrier, between the substrate (III) and (I). Pref. (II) consists of Ni81Fe19 "Fermalloy" (RTM) alloy, amorphous Fe80B2o, amorphous Co74Fe6B2o or an AlFeSi alloy. In particular, Co78.8Fe6.4B14.8 is used as (II) in conjunction with Co6oGd4o as (I). Layers of (I) and (II) are pref. formed on both sides of (III). (II) increases the stray field strength needed for readout and also avoids the possibility of distortion.