Abstract: The recording medium according to the invention has a magnetic recording layer, an exchange coupling layer and an enhancement or bias layer with an anisotropy orthogonal to the recording layer. The enhancement layer is designed to have no significant remanent magnetization and preferably to saturate under the write head. The enhancement layer creates an exchange field normal to the anisotropy of the recording layer and has the effect of rotating the magnetization of the recording layer and lowering the required switching field, i.e., the coercivity. The invention can be embodied in a longitudinal recording medium or a perpendicular recording medium. The exchange coupling can either ferromagnetic or antiferromagnetic. The bias layer has a high KuV and anisotropy and is designed to have high thermal stability and minimize the rotation of magnetization with the head field.

Abstract: A method for fabricating sliders (magnetic heads) with a recessed surface around a magnetic feature such as the active components of the write head on the air-bearing surface (ABS) is described. An embodiment of the method applies a positive photoresist to the exposed ABS surface, a magnetic field is applied, then liquid ferrofluid is applied on top of the photoresist. The pole pieces around the write gap will interact with the applied magnetic field so that the field gradient is highest around the write gap and the mobile ferrofluid will preferentially collect in the areas of the surface having the highest magnetic field gradient. The opaque magnetic particles in the ferrofluid form an optical ferrofluid mask over the photoresist around the write gap. The unmasked surface of the slider is milled which results in the recession of material around the write gap.

Abstract: A method of longitudinal recording using a medium with a magnetically soft underlayer is described. The method includes lowering the longitudinal coercivity in a magnetic domain in the magnetic recording medium by generating a vertical component of magnetic flux in the magnetic recording medium and writing a longitudinal orientation in the magnetic domain in the magnetic recording medium by generating a larger horizontal component of magnetic flux in the magnetic recording medium using the write head. Optionally the method further includes magnetically saturating the magnetically soft underlayer after lowering the longitudinal coercivity to limit the vertical component of the magnetic flux. The recording medium has a magnetic recording layer, a spacer layer and a soft underlayer. In one embodiment the soft underlayer is an antiferromagnetically coupled magnetic layer stack with two soft magnetic layers separated by a non-magnetic spacer layer selected to achieve the antiferromagnetic coupling.