High HC reference layer structure for self-pinned GMR heads

• US 7,221,545 B2
• Filed: 02/18/2004
• Issued: 05/22/2007
• Est. Priority Date: 02/18/2004
• Status: Expired due to Fees

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Inventors: Gill, Hardayal Singh
• Primary Examiner(s): KLIMOWICZ, WILLIAM JOSEPH
• Application Number:
  US10/781,232
• Publication Number:
  US 20050180059A1
• Time in Patent Office: 1,189 Days
• Field of Search: 360/324.12, 360/324.11, 360/324.2, 360/324.1
• US Class Current: 360/324.11
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/3906 Details related to the use of magnetic thin film layers or to their effects
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction

Abstract

A magnetic head having a free layer, an antiparallel (AP) pinned layer structure spaced apart from the free layer, and a high coercivity structure. The high coercivity structure pins a magnetic orientation of the AP pinned layer structure. The high coercivity structure includes a layer of high coercivity material, and an amorphous layer positioned between the high coercivity material and the AP pinned layer structure.

Claims

1. A magnetic head, comprising:

a free layer;

an antiparallel (AP) pinned layer structure spaced apart from the free layer; and

a high coercivity structure positioned towards the AP pinned layer structure on an opposite side thereof relative to the free layer, the high coercivity structure pinning a magnetic orientation of the AP pinned layer structure,

wherein a magnetic thickness of the high coercivity structure and a pinned layer of the AP pinned layer structure positioned closest thereto is about equal to a magnetic thickness of a pinned layer of the AP pinned layer structure positioned farthest front the high coercivity structure.

2. A head as recited in claim 1, wherein the AP pinned layer structure includes at least two pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers being separated by an AP coupling layer.

3. A head as recited in claim 2, wherein the pinned layers of the AP pinned layer structure are formed of CoFe.

4. A head as recited in claim 1, wherein the high coercivity structure includes a layer of CoPtCr.

5. A head as recited in claim 4, wherein the high coercivity structure further includes a seed layer of magnetic material under the CoPtCr, the seed layer allowing proper growth of the CoPtCr.

6. A head as recited in claim 1, wherein the head forms part of a GMR head.

7. A head as recited in claim 1, wherein the head forms part of a CPP GMR sensor.

8. A head as recited in claim 1, wherein the head forms part of a CIP GMR sensor.

9. A head as recited in claim 1, wherein the head forms part of a tunnel valve sensor.

10. A magnetic storage system, comprising:

magnetic media;

at least one head for reading from and writing to the magnetic media, each head having;

a sensor having the structure recited in claim 1;

a writer coupled to the sensor;

a slider for supporting the head; and

a control unit coupled to the head for controlling operation of the head.

11. A magnetic head, comprising:

a free layer;

an antiparallel (AP) pint ed layer structure spaced apart from the free layer; and

a high coercivity structure positioned towards the AP pinned layer structure on an opposite side thereof relative to the free layer, the high coercivity structure pinning a magnetic orientation of the AP pinned layer structure,

wherein the AP pinned layer structure includes at least two pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers being separated by an AP coupling layer;

wherein a magnetic thickness of the high coercivity structure and the pinned layer of the AP pinned layer structure positioned closest thereto is about equal to a magnetic thickness of the pinned layer of the AP pinned layer structure positioned farthest from the high coercivity structure.

12. A magnetic head, comprising:

a free layer;

an antiparallel (AP) pinned layer structure spaced apart from the free layer; and

a high coercivity structure positioned towards the AP pinned layer structure on an opposite side thereof relative to the free layer, the high coercivity structure pinning a magnetic orientation of the AP pinned layer structure,

wherein the high coercivity structure includes a layer of CoPtCr,

wherein the high coercivity structure further includes an amorphous layer positioned between the layer of CoPtCr and the AP pinned layer structure.

13. A head as recited in claim 12, wherein the amorphous layer comprises CoFeX, where X is selected from a group consisting of Nb, Zn and Hf.

14. A magnetic head, comprising:

a free layer;

an antiparallel (AP) pinned layer structure spaced apart from the free layer;

a layer of CoPtCr positioned towards the AP pinned layer structure on an opposite side thereof relative to the free layer layer of CoPtCt pinning a magnetic orientation of the AP pinned layer structure; and

an amorphous layer positioned between the layer of CoPtCr and the AP pinned layer structure.

15. A head as recited in claim 14, wherein the AP pinned layer structure includes at least two pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers being separated by an AP coupling layer.

16. A head as recited in claim 15, wherein the pinned layers of the AP pinned layer structure are formed of CoPe.

17. A head as recited in claim 15, wherein a magnetic thickness of the layer of CoPtCr, amorphous layer, and the pinned layer of the AP pinned layer structure positioned closest to the amorphous layer is about equal to a magnetic thickness of the pinned layer of the AP pinned layer structure positioned farthest from the amorphous layer.

18. A head as recited in claim 14, wherein the amorphous layer comprises CoFeX, where X is selected from a group consisting of Nb, Zn and Hf.

19. A head as recited in claim 14, further comprising a seed layer of magnetic material upon which the CoPtCr is formed.

20. A head as recited in claim 14, wherein the head forms parts of a GMR head.

21. A head s recited in claim 14, wherein the head forms part of a CPP GMR sensor.

22. A head as recited in claim 14, wherein the head forms part of a CIP GMR sensor.

23. A head as recited in claim 14, wherein the head forms part of a tunnel valve sensor.

24. A magnetic storage system comprising:

magnetic media;

at least one head for reading from and writing to the magnetic media, each head having;

a sensor having the structure recited in claim 14,

a writer coupled to the sensor;

a slider for supporting the head; and

a control unit coupled to the head for controlling operation of the head.