Write head with magnetization controlled by spin-polarized electron current

• US 6,809,900 B2
• Filed: 08/30/2001
• Issued: 10/26/2004
• Est. Priority Date: 01/25/2001
• Status: Expired due to Fees

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Covington, Mark William
• Primary Examiner(s): Chen, Tianjie
• Application Number:
  US09/943,329
• Publication Number:
  US 20020135935A1
• Time in Patent Office: 1,153 Days
• Field of Search: 360/126, 360/125, 360/319, 360/324.2, 360/321
• US Class Current: 360/125.01
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/02 Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
• CPC Class Codes: G11B 5/09 Digital recording
• CPC Class Codes: G11B 5/3103 Structure or manufacture of integrated heads or heads mechanically assembled and electrically connected to a support or housing
• CPC Class Codes: G11B 5/3109 Details G11B5/3103 takes precedence

Abstract

A write head for a disk drive includes a first layer of magnetic material having a fixed magnetization aligned in a first direction, a second layer of magnetic material having a changeable magnetization aligned in a quiescent state in a second direction orthogonal to the first direction, a first non-magnetic layer positioned between the first layer of magnetic material and the second layer of magnetic material, electrodes for connection to a current supply for passing an electric current through the first layer of magnetic material, the first non-magnetic layer, and the second layer of magnetic material for switching the changeable magnetization of the second layer, and an arm for positioning a first edge of the second layer of magnetic material adjacent to a magnetic recording medium, whereby the magnetization of the second layer of magnetic material affects magnetization of the magnetic recording medium. A method of recording information bits in a magnetic recording medium using the write head is also included.

Claims

1. A write head comprising:

a first layer of magnetic material having a fixed magnetization aligned in a first direction;

a second layer of magnetic material having a changeable magnetization aligned in a quiescent state in a second direction orthogonal to the first direction;

a first non-magnetic layer positioned between the first layer of magnetic material and the second layer of magnetic material;

means for connection to a current supply for passing an electric current through the first layer of magnetic material, the first non-magnetic layer, and the second layer of magnetic material for switching the changeable magnetization of the second layer of magnetic material; and

means for positioning a first edge of the second layer of magnetic material adjacent to a magnetic recording medium, whereby the magnetization of the second layer of magnetic material affects magnetization of the magnetic recording medium.

2. A write head according to claim 1, further comprising:

means for biasing the direction of magnetization of the first layer of magnetic material.

3. A write head according to claim 1, wherein the means for connection to a current supply comprises:

a first conductor electrically connected to the first layer of magnetic material; and

a second conductor electrically connected to the second layer of magnetic material.

4. A write head according to claim 1, further comprising:

a ferromagnetic yoke for conducting magnetic flux passing through the second layer of magnetic material and through the magnetic recording medium.

5. A write head according to claim 1, further comprising:

a third layer of magnetic material having a fixed magnetization aligned parallel to the first direction; and

a second non-magnetic layer positioned between the third layer of magnetic material and the second layer of magnetic material.

6. A write head according to claim 5, wherein the means for connection to a current supply comprises:

a first conductor electrically connected to the first layer of magnetic material; and

a second conductor electrically connected to the third layer of magnetic material.

7. A write head according to claim 1, further comprising:

a third layer of magnetic material having a fixed magnetization aligned parallel to the first direction;

a fourth layer of magnetic material having a changeable magnetization aligned in a quiescent state in a second direction orthogonal to the first direction;

a second non-magnetic layer positioned between the third layer of magnetic material and the fourth layer of magnetic material; and

a third non-magnetic layer positioned between the fourth layer of magnetic material and the second layer of magnetic material.

8. A write head according to claim 7, wherein the means for connection to a current supply comprises:

a first conductor electrically connected to the first layer of magnetic material; and

a second conductor electrically connected to the third layer of magnetic material.

9. A write head according to claim 1, further comprising:

a near field antenna positioned adjacent to the magnetic recording medium.

10. A write head comprising:

a first layer of magnetic material having a fixed magnetization aligned in a first direction;

a second layer of magnetic material having a changeable magnetization aligned in a quiescent state in a second direction orthogonal to the first direction;

a first non-magnetic layer positioned between the first layer of magnetic material and the second layer of magnetic material;

a first conductor electrically connected to the first layer of magnetic material;

a second conductor electrically connected to the second layer of magnetic material;

wherein an electric current passing through the first layer of magnetic material, the first non-magnetic layer, and the second layer of magnetic material switches the changeable magnetization of the second layer of magnetic material; and

wherein the magnetization of the second layer of magnetic material affects magnetization of an adjacent magnetic recording medium.

11. A write head according to claim 10, further comprising:

a permanent magnet for biasing the direction of magnetization of the first layer of magnetic material.

12. A write head according to claim 10, further comprising:

an antiferromagnet for biasing the direction of magnetization of the first layer of magnetic material.

13. A write head according to claim 10, further comprising:

a ferromagnetic yoke for conducting magnetic flux passing through the second layer of magnetic material and through the magnetic recording medium.

14. A write head according to claim 10, further comprising:

a near field antenna positioned adjacent to the magnetic recording medium.

15. A write head comprising:

a first layer of magnetic material having a fixed magnetization aligned in a first direction;

a second layer of magnetic material having a changeable magnetization aligned in a quiescent state in a second direction orthogonal to the first direction;

a first non-magnetic layer positioned between the first layer of magnetic material and the second layer of magnetic material;

a third layer of magnetic material having a fixed magnetization aligned parallel to the first direction;

a second non-magnetic layer positioned between the third layer of magnetic material and the second layer of magnetic material;

a first conductor electrically connected to the first layer of magnetic material;

a second conductor electrically connected to the third layer of magnetic material;

wherein an electric current passing through the first layer of magnetic material, the first non-magnetic layer, and the second layer of magnetic material switches the changeable magnetization of the second layer of magnetic material; and

wherein the magnetization of the second layer of magnetic material affects magnetization of an adjacent magnetic recording medium.

16. A write head according to claim 15, further comprising:

a permanent magnet for biasing the direction of magnetization of the first layer of magnetic material.

17. A write head according to claim 15, further comprising:

an antiferromagnet for biasing the direction of magnetization of the first layer of magnetic material.

18. A write head according to claim 15, further comprising:

a ferromagnetic yoke for conducting magnetic flux passing through the second layer of magnetic material and through the magnetic recording medium.

19. A write head according to claim 15, further comprising:

a near field antenna positioned adjacent to the magnetic recording medium.

20. A write head comprising:

a first layer of magnetic material having a fixed magnetization aligned in a first direction;

a second layer of magnetic material having a changeable magnetization aligned in a quiescent state in a second direction orthogonal to the first direction;

a first non-magnetic layer positioned between the first layer of magnetic material and the second layer of magnetic material;

a third layer of magnetic material having a fixed magnetization aligned parallel to the first direction;

a fourth layer of magnetic material having a changeable magnetization aligned in a quiescent state in a second direction orthogonal to the first direction;

a second non-magnetic layer positioned between the third layer of magnetic material and the fourth layer of magnetic material; and

a third non-magnetic layer positioned between the fourth layer of magnetic material and the second layer of magnetic material;

a first conductor electrically connected to the first layer of magnetic material;

a second conductor electrically connected to the third layer of magnetic material;

wherein an electric current passing through the first layer of magnetic material, the first non-magnetic layer, and the second layer of magnetic material switches the changeable magnetization of the second layer of magnetic material; and

wherein the magnetization of the second layer of magnetic material affects magnetization of an adjacent magnetic recording medium.

21. A write head according to claim 20, further comprising:

a permanent magnet for biasing the direction of magnetization of the first layer of magnetic material.

22. A write head according to claim 20, further comprising:

an antiferromagnet for biasing the direction of magnetization of the first layer of magnetic material.

23. A write head according to claim 20, further comprising:

a ferromagnetic yoke for conducting magnetic flux passing through the second layer material and through the magnetic recording medium.

24. A write head according to claim 20, further comprising:

a near field antenna positioned adjacent to the magnetic recording medium.