Method for biasing magnetoresistive sensor with decoupled hard bias multilayers
AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorsMarie-Claire Cyrille, Meng Ding, Kuok San Ho, Prakash Kasiraj, Ernesto Marinero, James Lamar Nix
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Abstract
A magnetic sensor is provided, having two bias layers separated by a decoupling layer to eliminate exchange coupling between the bias layers. The two bias layers may have differing coercivities, such that the biases provided by the bias layers to the free layer are independently adjustable. The grain structures of the two bias layers may be substantially decorrelated by the decoupling layer.
Claims7
A method for setting a remanent magnetization of a bias subassembly for biasing a free layer of a magnetic sensor, the method comprising:
- providing within the bias subassembly a first bias layer of ferromagnetic material having a coercivity Hc1 and providing a first bias to the free layer;
- providing within the bias subassembly a second bias layer of ferromagnetic material having a coercivity Hc2 greater than Hc1 and providing a second bias to the free layer;
- providing within the bias subassembly a decoupling layer disposed between the first and second bias layers to substantially eliminate exchange coupling between the first and second bias layers;
- and
- applying a first bias magnetic field having a magnetic field strength H1 to the bias subassembly, wherein H1 is greater than Hc1 and H1 is less than Hc2;
- whereby the first bias is altered, and the second bias is substantially unaltered.
Dependencies are inferred from the claim text.