Resettable Instack Bias Using Direct Ferromagnetic / Antiferromagnetic Coupling
Original Publication Date: 2003-Feb-02
Included in the Prior Art Database: 2003-Jun-21
Disclosed is an in-stack longitudinal bias scheme for magnetic multilayer sensors, utilizing a direct ferromagnetic or antiferromagnetic coupling to a biasing layer in close proximity to the sensing (free) layer of the sensor, and the shape anisotropy of the biasing layer itself. The ferromagnetic or antiferromagnetic coupling is achieved by properly adjusting/choosing the thickness and material of the non-magnetic spacer. By using direct coupling between the biasing layer and the free layer, our invention significantly simplify the complexity of the in-stack biasing structure. The result in an in-stach stabilized sensor structure of great simplicity, well suited for example to magnetic recording read heads with narrow shield-to-shield spacings as used for magnetic recording at densities > 100 Gbit/in2.