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US 5,705,973 AGranted
Bias-free symmetric dual spin valve giant magnetoresistance transducer
AssigneeRead-Rite Corporation
InventorsSamuel W. Yuan, Hua-Ching Tong, Francis H. Liu, Minshen Tan
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Abstract
A giant magnetoresistive dual spin valve sensor employs at least one magnetic biasing layer located adjacent to an antiferromagnetic layer in the spin valve structure which includes two pinned ferromagnetic layers. The antiferromagnetic layer simultaneously pins the biasing layer and the ferromagnetic layer nearest the antiferromagnetic layer. This structure eliminates the bias point offset present in prior dual spin valve sensors.
Claims7
A dual gap magnetoresistive sensor comprising:
- a free ferromagnetic layer;
- first and second spacers adjacent to opposing first and second surfaces of said ferromagnetic layer respectively;
- first and second pinned ferromagnetic layers adjacent to said first and second spacers respectively, wherein the directions of magnetization of said pinned layers are the same, and the direction of magnetization of said free layer is perpendicular to that of said pinned layers at zero applied magnetic field;
- first and second antiferromagnetic layers adjacent to said first and second pinned ferromagnetic layers respectively;
- and
- a magnetic biasing means disposed adjacent to at least one of said antiferromagnetic layers, the direction of magnetization of said biasing means being opposite to that of said pinned ferromagnetic layers;
- so that any stray field generated by said pinned ferromagnetic layers is eliminated and the biasing level of the sensor is independent of sense current.
4 more elements
Dependencies are inferred from the claim text.