GMR enhancing seedlayer for self pinned spin valves

• US 20050063105A1
• Filed: 09/24/2003
• Published: 03/24/2005
• Est. Priority Date: 09/24/2003
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Hitachi Global Storage Technologies Incorporated (Western Digital Corporation)
• Inventors: Pinarbasi, Mustafa Michael
• Granted Patent: US 6,961,224 B2
• Time in Patent Office: Days
• US Class Current: 360/324.110
• 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: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• 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 5/3954 the active elements transducing on a single track

Abstract

A magnetic head includes a seed layer structure comprising Al₂O₃, Ta, and NiFeCr seed layers. An antiparallel (AP) pinned layer structure is formed above the NiFeCr seed layer. A free layer is positioned above the AP pinned layer structure.

Claims

1. A magnetic head, comprising:

a seed layer structure comprising Al₂O₃, Ta, and NiFeCr seed layers;

an antiparallel (AP) pinned layer structure formed above the NiFeCr seed layer;

and

a free layer positioned above the AP pinned layer 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 AP pinned layers are constructed of CoFe and Co.

4. A head as recited in claim 3, wherein the pinned layer closest to the seed layer structure includes CoFe.

5. A head as recited in claim 2, wherein the AP pinned layers are both constructed of Co.

6. A head as recited in claim 2, wherein the AP pinned layers are both constructed of CoFe.

7. A head as recited in claim 2, wherein the AP pinned layers are constructed of materials selected to maximize a magnetostriction of the AP pinned layers.

8. A head as recited in claim 1, wherein a thickness of the NiFeCr seed layer is selected to maximize a GMR signal.

9. A head as recited in claim 1, wherein the head has at least a 10% stronger GMR signal over a head having a substantially similar structure except for the seed layers.

10. A head as recited in claim 1, wherein the head has at least a 10% stronger GMR signal over a head having a substantially similar structure except for materials used to form the pinned layers.

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

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

19. 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 write element coupled to the sensor;

a slider for supporting the head; and

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

13. A magnetic head, comprising:

a seed layer structure comprising Al₂O₃, Ta, and NiFeCr seed layers;

an antiparallel (AP) pinned layer structure formed above the NiFeCr seed layer,

wherein the AP pinned layers are constructed of CoFe and Co, wherein the pinned layer closest to the seed layer structure includes CoFe; and

a free layer positioned above the AP pinned layer structure.

14. A head as recited in claim 13, wherein the head has at least a 10% stronger GMR signal over a head having a substantially similar structure except for the seed layers.

15. A head as recited in claim 13, wherein the head has at least a 10% stronger GMR signal over a head having a substantially similar structure except for materials used to form the pinned layers.

16. A head as recited in claim 13, wherein the head forms part of a GMR head.

17. A magnetic head, comprising:

a seed layer structure comprising Al₂O₃, Ta, and NiFeCr seed layers;

an antiparallel (AP) pinned layer structure formed above the NiFeCr seed layer,

wherein the AP pinned layers are constructed of Co and Co; and

a free layer positioned above the AP pinned layer structure.

18. A head as recited in claim 18, wherein the head has at least a 10% higher positive magnetostriction over a head having a substantially similar structure except for the seed layers.