Spin valve magnetic head with three underlayers

• US 6,833,981 B2
• Filed: 02/22/2002
• Issued: 12/21/2004
• Est. Priority Date: 06/28/2001
• Status: Expired due to Fees

• Current Assignee: Hitachi Global Storage Technologies Japan Limited (Western Digital Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Tajima, Yasunari, Noguchi, Shin, Suwabe, Shigekazu, Shigematsu, Satoshi
• Primary Examiner(s): Renner, Craig A.
• Assistant Examiner(s): Magee, Christopher R
• Application Number:
  US10/079,427
• Publication Number:
  US 20030002228A1
• Time in Patent Office: 1,033 Days
• Field of Search: 360/324, 360/324.1, 360/324.11, 360/324.12, 296/031.4, 204/192.11
• US Class Current: 360/324.1
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures

Abstract

A spin valve magnetic head, providing on a substrate, a laminated structure that has an antiferromagnetic layer, fixation layer, non-magnetic layer and unconstraint layer, and having a first underlayer of Ta, a second underlayer of NiFeCr and a third underlayer of NiFe, which underlayers are interposed between the substrate and the laminated structure.

Claims

1. A spin valve magnetic head, providing on a substrate, a laminated structure that has an antiferromagnetic layer, fixation layer, non-magnetic layer and unconstraint layer, comprising:

a first underlayer of Ta;

a second underlayer of NiFeCr; and

a third underlayer of NiFe, said first, second and third underlayers being interposed between said substrate and said laminated structure.

3. The spin valve magnetic head according to claim 1, wherein the crystal structure of said NiFeCr of said second underlayer is a bcc structure.

5. The spin valve magnetic head according to claim 1, wherein the crystal structure of said NiFeCr of said second underlayer has a (110) orientation.

7. The spin valve magnetic head according to claim 1, wherein the average crystal particle size measured in the film in-plane direction of said NiFeCr of said second underlayer is at least 10 nm.

8. The spin valve magnetic head according to claim 3, wherein the average crystal particle size measured in the film in-plane direction of said NiFeCr of said second underlayer is at least 10 nm.

11. The spin valve magnetic head according to any of claim 1, claim 3, claim 7 or claim 8, wherein the elements in the empirical formula (Nia-Feb)_x-Cry, when said formula represents said NiFeCr in said underlayers, are in the ranges 45<

a<

100, 55<

b<

100, 50<

x<

80, 20<

y<

50, a+b=100, x+y=100 in terms of at %, and the film thickness is in the range 3.5 nm-6 nm.

25. The spin valve magnetic head according to any of claim 1, claim 3, claim 7, claim 8, claim 13, claim 15, claim 19 or claim 20, wherein the elements in the empirical formula Ni_x-Fey, when said formula represents said NiFe in said underlayers, are in the ranges 70<

x−

90, 10<

y−

30, x+y=100 in terms of at %, and the film thickness is in the range 0.25 nm-2.0 nm.

27. The spin valve magnetic head according to any of claim 1, claim 3, claim 5, claim 7, claim 8, claim 13, claim 15 and claim 17, wherein the film thickness of said Ta of said first underlayer is at least 0.25 nm.

29. The spin valve magnetic head according to any of claim 1, claim 3, claim 5, claim 7, claim 8, claim 13, claim 15 and claim 17, wherein said unconstraint layer comprises a magnetic layer including Co or CoFe alloy.

31. The spin valve magnetic head according to any of claim 1, claim 3, claim 5, claim 7, claim 8, claim 13, claim 15 and claim 17, wherein said fixation layer comprises at least two magnetic layers separated by a non-magnetic layer, and the magnetic layers are combined such that their magnetic moments are antiparallel.

33. The spin valve magnetic head according to any of claim 1, claim 3, claim 5, claim 7, claim 8, claim 13, claim 15 and claim 17, wherein said antiferromagnetic layer is any of PtMn, NiMn, IrMn or PdPtMn.

2. A dual spin valve magnetic head, providing on a substrate, a laminated structure that has a first antiferromagnetic layer, first fixation layer, first non-magnetic layer, unconstraint layer, second non-magnetic layer, second fixation layer and second antiferromagnetic layer, comprising:

a first underlayer of Ta;

a second underlayer of NiFeCr; and

a third underlayer of NiFe, said first, second and third underlayers being interposed between said substrate and said laminated structure.

4. The dual spin valve magnetic head according to claim 2, wherein the crystal structure of said NiFeCr of said second underlayer is a bcc structure.

6. The dual spin valve magnetic according to claim 2, wherein the crystal structure of said NiFeCr of said second underlayer has a (110) orientation.

9. The dual spin valve magnetic head according to claim 2, wherein the average crystal particle size measured in the film in-plane direction of said NiFeCr of said second underlayer is at least 10 nm.

10. The dual spin valve magnetic head according to claim 6, wherein the average crystal particle size measured in the film in-plane direction of said NiFeCr of said second underlayer is at least 10 nm.

12. The dual spin valve magnetic head according to any of claim 2, claim 6, claim 9 or claim 10, wherein the elements in the empirical formula (Nia-Feb)_x-Cry, when said formula represents the NiFeCr in said underlayers, are in the ranges 45<

a<

100, 55<

b<

100, 50<

x<

80, 20<

y<

50, a+b=100, x+y=100 in terms of at %, and the film thickness is in the range 3.5 nm-6 nm.

28. The dual spin valve magnetic head according to any of claim 2, claim 4, claim 6, claim 9, claim 10, claim 14, claim 16 and claim 18, wherein the film thickness of said Ta of said first underlayer is at least 0.25 nm.

30. The dual spin valve magnetic head according to any of claim 2, claim 4, claim 6, claim 9, claim 10, claim 14, claim 16 and claim 18, wherein said unconstraint layer comprises a magnetic layer including Co or CoFe alloy.

32. The dual spin valve magnetic head according to any of claim 2, claim 4, claim 6, claim 9, claim 10, claim 14, claim 16 and claim 18, wherein said fixation layer comprises at least two magnetic layers separated by a non-magnetic layer, and the magnetic layers are combined such that their magnetic moments are antiparallel.

34. The dual spin valve magnetic head according to any of claim 2, claim 4, claim 6, claim 9, claim 10, claim 14, claim 16 and claim 18, wherein said antiferromagnetic layer is any of PtMn, NiMn, IrMn or PdPtMn.

13. A spin valve magnetic head, providing on a substrate, a laminated structure that has an antiferromagnetic layer, fixation layer, non-magnetic layer and unconstraint layer, comprising:

a first underlayer of Ta;

a second underlayer of NiCr; and

a third underlayer of NiFe, said first, second and third underlayers being interposed between said substrate and said laminated structure.

15. The spin valve magnetic head according to claim 13, wherein the crystal structure of said NiCr in said second underlayer is a bcc structure.

17. The spin valve magnetic head according to claim 15, wherein the crystal structure of said NiCr in said second underlayer has a (110) orientation.

19. The spin valve magnetic head according to claim 13, wherein the average crystal particle size measured in the film in-plane direction of said NiCr of said second underlayer is at least 10 nm.

20. The spin valve magnetic head according to claim 15, wherein the average crystal particle size measured in the film in-plane direction of said NiCr of said second underlayer is at least 10 nm.

23. The spin valve magnetic head according to any of claim 13, claim 15, claim 19 or claim 20, wherein the elements in the empirical formula Ni_x-Cry, when said formula represents said NiCr in said underlayers, are in the ranges 50<

x<

80, 20<

y<

50, x+y=100 in terms of at %, and the film thickness is in the range 3.5 nm-6 nm.

14. A dual spin valve magnetic head, providing on a substrate a laminated structure that has a first antiferromagnetic layer, first fixation layer, first non-magnetic layer, unconstraint layer, second non-magnetic layer, second fixation layer and second antiferromagnetic layer, comprising:

a first underlayer of Ta;

a second underlayer of NiCr; and

a third underlayer of NiFe, said first, second and third underlayers being interposed between said substrate and said laminated structure.

16. The dual spin valve magnetic head according to claim 14, wherein the crystal structure of said NiCr in said second underlayer is a bcc structure.

18. The dual spin valve magnetic head according to claim 16, wherein the crystal structure of said NiCr in said second underlayer has a (110) orientation.

21. The dual spin valve magnetic head according to claim 14, wherein the average crystal particle size measured in the film in-plane direction of said NiCr of said second underlayer is at least 10 nm.

22. The dual spin valve magnetic head according to claim 18, wherein the average crystal particle size measured in the film in-plane direction of said NiCr of said second underlayer is at least 10 nm.

24. The dual spin valve magnetic head according to any of claim 14, claim 18, claim 21 or claim 22, wherein the elements in the empirical formula Ni_x-Cry, when said formula represents said NiCr in said underlayers, are in the ranges 50<

x<

80, 20<

y<

50, x+y=100 in terms of at %, and the film thickness is in the range 3.5 nm-6 nm.

26. The dual spin valve magnetic head as defined in any of claim 2, claim 6, claim 14 or claim 18, wherein the elements in the empirical formula Ni_x-Fey, when said formula represents the NiFe in said underlayers, are in the ranges 70<

x<

90, 10<

y<

30, x+y=100 in terms of at %, and the film thickness is in the range 0.25 nm-2.0 nm.