Abstract: A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films antiferromagnetically coupled together across a nonferromagnetic spacer film. The magnetic moments of the two antiferromagnetically-coupled films are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of the recording layer is the difference in the Mrt values of the two ferromagnetic films. This reduction in Mrt is accomplished without a reduction in the thermal stability of the recording medium because the volumes of the grains in the antiferromagnetically-coupled films add constructively. In a magnetic recording rigid disk application, the magnetic layer comprises two ferromagnetic films, each a granular film of a sputter deposited CoPtCrB alloy, separated by a Ru spacer film having a thickness to maximize the antiferromagnetic exchange coupling between the two CoPtCrB films.

Abstract: A longitudinal bias structure to be placed adjacent a ferromagnetic free layer or a sense layer which is responsive to an external magnetic field and belongs to a magnetic sensor, for example a magnetic readback sensor such as an anisotropic magnetoresistive (AMR) sensor, giant magnetoresistive (GMR) sensor such as GMR spin valve sensor or GMR multilayer sensor or in tunnel valve sensor. The longitudinal bias structure is built up of a top ferromagnetic bias layer of first thickness t1 having a first magnetic moment M1, a bottom ferromagnetic bias layer of second thickness t2 having a second magnetic moment M2 which is anti-parallel to first magnetic moment M1 of the top ferromagnetic bias layer, and an exchange-coupling layer disposed between the top and bottom bias layers.