Spin-valve film, magnetoresistance-effect device and magnetoresistance-effect magnetic head

• US 6,287,709 B1
• Filed: 09/16/1999
• Issued: 09/11/2001
• Est. Priority Date: 09/21/1998
• Status: Expired due to Fees

• Current Assignee: New Energy and Industrial Technology Development Organizatio
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Mizuguchi, Tetsuya
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): LA VILLA, MICHAEL EUGENE
• Application Number:
  US09/397,068
• Time in Patent Office: 726 Days
• Field of Search: 428/662, 428/660, 428/680, 428/681, 428/615, 428/661, 428/692, 428/693, 428/697, 428/699, 428/900, 428/611, 428/679, 428/682, 360/113, 360/126, 252/62.55, 117/939, 117/937, 365/158
• US Class Current: 428/811.2
• CPC Class Codes: B32B 15/01 all layers being exclusively metallic making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00
• 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 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: H01F 10/324 Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
• CPC Class Codes: H01F 10/3268 the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn
• CPC Class Codes: H01F 10/3295 Spin-exchange coupled multilayers wherein the magnetic pinned or free layers are laminated without anti-parallel coupling within the pinned and free layers
• CPC Class Codes: Y10T 428/1121 Multilayer
• CPC Class Codes: Y10T 428/12937 Co- or Ni-base component next to Fe-base component
• CPC Class Codes: Y10T 428/12944 Ni-base component
• CPC Class Codes: Y10T 428/12951 Fe-base component
• CPC Class Codes: Y10T 428/12958 Next to Fe-base component

Abstract

A spin-valve film which enables a high output to be obtained and thermal stability to be improved without a necessity of reducing the thickness of films which constitute the spin-valve film, a spin valve type magnetoresistance-effect device and a magnetic head comprising the spin valve type magnetoresistance-effect device. A spin-valve film according to the present invention comprises a fixed layer in which a direction of magnetization is to be directed to substantially a predetermined direction; a non-magnetic layer; and a free layer in which a direction of magnetization is to be changed by an external magnetic field, wherein the free layer comprises at least a laminate film having a Ta film and a NiFeTa film.

Claims

1. A spin-valve film comprising:

a fixed layer in which a direction of magnetization is substantially fixed in a first direction;

a free layer in which a direction of magnetization can be changed relative to the first direction by an external magnetic field; and

a non-magnetic layer between the fixed layer and the free layer, wherein,

said free layer comprises at least a laminate film having a Ta film and a (NiFe)<sub>1−

x</sub>Ta_x film, and x is 0.09 to 0.16.

2. A spin-valve film according to claim 1, wherein said free layer further comprises a CoFe film.

3. A magnetoresistance-effect device comprising:

a spin-valve film comprising a fixed layer in which a direction of magnetization is substantially fixed in a first direction, a free layer in which a direction of magnetization can be changed by an external magnetic field, and a non-magnetic layer between the fixed layer and the free layer, wherein an external magnetic field is detected by detecting change in the resistance of said spin-valve film, wherein said free layer of said spin-valve film comprises at least a laminate film having a Ta film and a (NiFe)<sub>1−

x</sub>Ta_x film where x is 0.09 to 0.16.

4. A magnetoresistance-effect device according to claim 3, wherein said free layer further comprises a CoFe film.

5. A magnetoresistance-effect head comprising:

a magnetoresistance-effect device detecting an external magnetic field by detecting change in the resistance of a spin-valve film for detecting a magnetic of a signal obtained from a magnetic recording medium, wherein

said spin-valve film comprises a fixed layer in which a direction of magnetization is substantially fixed in a first direction, a free layer in which a direction of magnetization can be changed by an external field, and a non-magnetic layer between the fixed layer and the free layer; and

said free layer of said spin-valve film comprises at least a laminate film having a Ta film and a (NiFe)<sub>1−

x</sub>Ta_x film where is 0.09 to 0.16.

6. A magnetoresistance-effect magnetic head according to claim 5, wherein said free layer further comprises a CoFe film.