Claims
- 1. A magnetoresistive sensor comprising:
a first ferromagnetic free layer having a first quiescent state magnetization direction; a second ferromagnetic free layer overlapping a portion of the first elongated ferromagnetic free layer and having a second quiescent state magnetization direction angled generally orthogonal to the first quiescent state magnetization direction; and nonmagnetic spacer means positioned between the first ferromagnetic free layer and the second ferromagnetic free layer.
- 2. The magnetoresistive sensor of claim 1, wherein the first quiescent state magnetization direction and the second quiescent state magnetization direction are generally orthogonal with respect to each other due to shape anisotropy.
- 3. The magnetoresistive sensor of claim 2, wherein the first magnetization direction and the second magnetization direction rotate about their respective quiescent states in response to flux emanated from the rotating disc.
- 4. The magnetoresistive sensor of claim 1, wherein the nonmagnetic spacer means is a tunnel barrier.
- 5. The magnetoresistive sensor of claim 4, wherein flux emanated from the rotating disc produces a tunneling magnetoresistive (TMR) effect in the tunnel barrier.
- 6. The magnetoresistive sensor of claim 1, wherein the nonmagnetic spacer means is a conducting spacer.
- 7. The magnetoresistive sensor of claim 6, wherein flux emanated from the rotating disc produces a giant magnetoresistive (GMR) effect in the conducting spacer.
- 8. The magnetoresistive sensor of claim 1, wherein the nonmagnetic spacer means completely covers a top planar surface of the first ferromagnetic free layer.
- 9. The magnetoresistive sensor of claim 1, wherein the first ferromagnetic free layer and the second ferromagnetic free layer are each oriented at equal angles relative to the air bearing surface.
- 10. A read sensor having an air bearing surface for confronting a surface of a rotating disc, the read sensor comprising:
a first elongated free layer having an air bearing surface; a second elongated free layer having an air bearing surface and positioned such that the first elongated free layer and the second elongated free layer are oriented at an angle relative to the air bearing surface, and such that a portion of the second elongated ferromagnetic free layer overlaps a portion of the first elongated ferromagnetic free layer proximate to the air bearing surface to form a v-shape; and a nonmagnetic spacer positioned between the first elongated free layer and the second elongated free layer.
- 11. The magnetoresistive sensor of claim 10, wherein the first elongated ferromagnetic free layer and the second elongated ferromagnetic free layer are oriented at equal angles relative to the air bearing surface.
- 12. The magnetoresistive sensor of claim 10, wherein the nonmagnetic spacer means is a tunnel barrier.
- 13. The magnetoresistive sensor of claim 12, wherein flux emanated from the rotating disc produces a tunneling magnetoresistive (TMR) effect in the tunnel barrier.
- 14. The magnetoresistive sensor of claim 10, wherein the nonmagnetic spacer means is a conducting spacer.
- 15. The magnetoresistive sensor of claim 14, wherein flux emanated from the rotating disc produces a giant magnetoresistive (GMR) effect in the conducting spacer.
- 16. A magnetoresistive sensor having an air bearing surface for confronting a surface of a rotating disc, the magnetoresistive sensor comprising:
a first ferromagnetic free layer; a second ferromagnetic free layer positioned such that a quiescent state magnetization of the first elongated ferromagnetic free layer is aligned generally orthogonal to a quiescent state magnetization of the second elongated ferromagnetic free layer due to shape anisotropy; and a nonmagnetic spacer layer positioned between the first ferromagnetic free layer and the second ferromagnetic free layer.
- 17. The magnetoresistive sensor of claim 16, wherein the magnetization of the first ferromagnetic free layer and the magnetization of the second ferromagnetic free layer rotate about their respective quiescent bias states in response to flux emanated from the rotating disc.
- 18. The magnetoresistive sensor of claim 17, wherein rotation of the magnetization of the free layers produces a giant magnetoresistive effect.
- 19. The magnetoresistive sensor of claim 16, wherein the nonmagnetic spacer layer is a tunneling barrier.
- 20. The magnetoresistive sensor of claim 19, wherein flux emanated from the rotating disc produces a tunneling magnetoresistive (TMR) effect in the tunnel barrier.
- 21. The magnetoresistive sensor of claim 16, wherein the nonmagnetic spacer means is a conducting spacer.
- 22. The magnetoresistive sensor of claim 21, wherein flux emanated from the rotating disc produces a giant magnetoresistive (GMR) effect in the conducting spacer.
- 23. A magnetoresistive element comprising:
a first free layer having a shape anisotropy induced first magnetization direction; a second free layer overlapping a portion of the first free layer and having a shape anisotropy induced second magnetization direction, the second magnetization direction positioned at an angle relative to the first magnetization direction; and a spacer layer positioned between the overlapping portions of the first free layer and the second free layer.
- 24. The magnetoresistive element of claim 23, further comprising means connected to the first free layer and the second free layer for deriving a magnetoresistive signal.
- 25. The magnetoresistive element of claim 23, wherein the first magnetization direction and the second magnetization direction are generally orthogonal with respect to each other when the magnetoresistive element is in a quiescent state.
- 26. The magnetoresistive element of claim 23, wherein the angle between the first magnetization direction and the second magnetization direction changes in response to an external magnetic field.
- 27. The magnetoresistive element of claim 23, wherein resistance between the first free layer and the second free layer changes in response to an external magnetic field.
- 28. A method of forming a magnetoresistive sensor, the method comprising:
forming a first elongated ferromagnetic free layer having a first quiescent state magnetization direction; forming a nonmagnetic spacer layer over the first ferromagnetic free layer; forming a thin ferromagnetic protective layer over the nonmagnetic spacer layer; etching the thin ferromagnetic protective layer to expose a portion of the nonmagnetic spacer layer; and forming a second elongated ferromagnetic free layer having a second quiescent state magnetization direction over the thin ferromagnetic protective layer such that the first quiescent state magnetization direction is generally orthogonal to the second quiescent state magnetization direction and such that the combination of the first elongated ferromagnetic free layer, the nonmagnetic spacer layer, the thin ferromagnetic protective layer, and the second elongated ferromagnetic free layer forms the magnetoresistive sensor.
- 29. The method of claim 28, further comprising:
providing a lap monitor which corresponds to a shape of the magnetoresistive sensor; and lapping the lap monitor and the magnetoresistive sensor simultaneously to create an air bearing surface.
- 30. The method of claim 29, wherein the lap monitor includes a variable resistor and a target resistor such that the lap monitor and the magnetoresistive sensor are lapped until a resistance of the variable resistor equals a resistance of the target resistor.
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority from Provisional Application No. 60/380,636 filed May 15, 2002, for “‘V’-Shape Magnetic Field Sensor With Anisotropy Induced Orthognal Magnetic Alignment” by Victor B. Sapozhnikov, Taras G. Pokhil, Olle G. Heinonen, and Janusz J. Nowak.
Provisional Applications (1)
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Number |
Date |
Country |
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60380636 |
May 2002 |
US |