Differential VGMR sensor
AssigneeSeagate Technology LLC
InventorsBrenda Anne Everitt, Taras Grigorievich Pokhil
Life of this patent
Estimating the term…
Abstract
A Vertical Giant Magnetoresistive Sensor (VGMR) with two VGMR structures (61 A, 61 B), each responding differently to an external magnetic field, producing a differential signal proportional to the field. The magnetizations (M1, M1′, M2, M2′) in each of the sensors are oriented antiparallel. The antiparallel magnetization is attained by altering the magnetic compositions of the two structures, or adding an additional structure such as a permanent magnet or current strip (11) between the VGMR structures.
Claims19
An apparatus for reading data comprising:
- a first magnetoresistive element;
- a second magnetoresistive element formed substantially parallel to the first magnetoresistive element;
- a nonmagnetic single spacer adjacent to both the first and second magnetoresistive elements;
- wherein the first and second magnetoresistive elements are comprised of:
- a first magnetic layer;
- a second magnetic layer formed substantially parallel to the first magnetic layer;
- a permanent magnet formed between the first and second magnetoresistive elements and adjacent the nonmagnetic spacer;
- and
- a conductive spacer interposed between the first and second magnetic layers, wherein a bias current applied to the conductive spacer of the first magnetoresistive element is substantially equal to a bias current applied to the conductive spacer of the second magnetoresistive element.
The apparatus of claim 9 wherein the single layer is comprised of at least one of NiFe, CoFe, and NiFeCo.
A vertical giant magnetoresistive (VGMR) sensor, comprising:
- a first VGMR stack;
- a second VGMR stack;
- a nonmagnetic and nonconductive single spacer adjacent to both the first and second VGMR stacks;
- and
- a permanent magnet formed between the first and second VGMR stack and adjacent the spacer.
Dependencies are inferred from the claim text.