Magnetoresistance effect element, magnetic head and magnetic reproducing apparatus

• US 7,443,004 B2
• Filed: 11/22/2005
• Issued: 10/28/2008
• Est. Priority Date: 08/15/2001
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yoshikawa, Masatoshi, Yuasa, Hiromi, Sahashi, Masashi, Koui, Katsuhiko, Iwasaki, Hitoshi, Kamiguchi, Yuzo, Nagata, Tomohiko, Sakakubo, Takeo
• Primary Examiner(s): Ho; Tu-Tu V
• Application Number:
  US11/283,873
• Publication Number:
  US 20060071287A1
• Time in Patent Office: 1,071 Days
• Field of Search: 257/421, 257/E27.006
• US Class Current: 257/421
• 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 5/00 Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor G11B11/00 and G11B13/00 take precedence
• 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 10/30 characterised by the composition of the intermediate layers , e.g. seed, buffer, template, diffusion preventing, cap layers H01F10/06 and H01F10/32 take precedence
• CPC Class Codes: H01F 10/3227 Exchange coupling via one or more magnetisable ultrathin or granular films
• CPC Class Codes: H01F 10/3272 by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets
• 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: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

In a spin valve type element, an interface insertion layer (32, 34) of a material exhibiting large spin-dependent interface scattering is inserted in a location of a magnetically pinned layer (16) or a magnetically free layer (20) closer to a nonmagnetic intermediate layer (18). A nonmagnetic back layer (36) may be additionally inserted as an interface not in contact with the nonmagnetic intermediate layer to increase the output by making use of spin-dependent interface scattering along the interface between the pinned layer and the nonmagnetic back layer or between the free layer and the nonmagnetic back layer.

Claims

1. A magnetoresistance effect element comprising:

a magnetoresistance effect film including a magnetically pinned layer having a magnetic material film whose direction of magnetization is pinned substantially in one direction, a magnetically free layer having a magnetic material film whose direction of magnetization changes in response to an external magnetic field, a nonmagnetic metal intermediate layer located between said pinned layer and said free layer, and an anti-ferromagnetic layer configured to pin said magnetization of said magnetically pinned layer; and

a pair of electrodes electrically connected to said magnetoresistance effect film to supply a sense current perpendicularly to a film plane of said magnetoresistance effect film,

at least one of said pinned layer and said free layer including a thin-film insertion layer, and

said thin-film insertion layer being a binary alloy containing a quantity of iron (Fe) not less than 50 atomic % as the major component thereof, or a ternary alloy containing a quantity of iron (Fe) not less than 25 atomic % as the major component thereof, and said alloy having a body-centered cubic crystal structure.

2. The magnetoresistance effect element according to claim 1, wherein said alloy additionally contains a quantity of at least one kind of element selected from the group consisting of copper (Cu), silver (Ag), and gold (Au) not less than 0.1 atomic % and not exceeding 20 atomic %.

3. The magnetoresistance effect element according to claim 1, wherein a back insertion layer made of copper (Cu), gold (Au), silver (Ag), or an alloy combining at least two kinds of these metals is provided adjacent to an interface of said free layer not in contact with said nonmagnetic intermediate layer.

4. The magnetoresistance effect element according to claim 1, wherein said thin-film insertion layer adjoins said nonmagnetic metal intermediate layer.

5. A magnetic head comprising:

a magnetoresistance effect element comprising;

a magnetoresistance effect film including a magnetically pinned layer having a magnetic material film whose direction of magnetization is pinned substantially in one direction, a magnetically free layer having a magnetic material film whose direction of magnetization changes in response to an external magnetic field, a nonmagnetic metal intermediate layer located between said pinned layer and said free layer, and an anti-ferromagnetic layer configured to pin said magnetization of said magnetically pinned layer; and

a pair of electrodes electrically connected to said magnetoresistance effect film to supply a sense current perpendicularly to a film plane of said magnetoresistance effect film,

at least one of said pinned layer and said free layer including a thin-film insertion layer, and

said thin-film insertion layer being a binary alloy containing a quantity of iron (Fe) not less than 50 atomic % as the major component thereof, or a ternary alloy containing a quantity of iron (Fe) not less than 25 atomic % as the major component thereof, and said alloy having a body-centered cubic crystal structure.

6. The magnetic head according to claim 5, wherein said alloy additionally contains a quantity of at least one kind of element selected from the group consisting of copper (Cu), silver (Ag), and gold (Au) not less than 0.1 atomic % and not exceeding 20 atomic %.

7. The magnetic head according to claim 5, wherein a back insertion layer made of copper (Cu), gold (Au), silver (Ag), or an alloy combining at least two kinds of these metals is provided adjacent to an interface of said free layer not in contact with said nonmagnetic intermediate layer.

8. A magnetic reproducing apparatus which reads information magnetically recorded in a magnetic recording medium, comprising:

a magnetoresistance effect element comprising;

a magnetic head having a magnetoresistance effect film including a magnetically pinned layer having a magnetic material film whose direction of magnetization is pinned substantially in one direction, a magnetically free layer having a magnetic material film whose direction of magnetization changes in response to an external magnetic field, a nonmagnetic metal intermediate layer located between said pinned layer and said free layer, and an anti-ferromagnetic layer configured to pin said magnetization of said magnetically pinned layer; and

a pair of electrodes electrically connected to said magnetoresistance effect film to supply a sense current perpendicularly to a film plane of said magnetoresistance effect film,

at least one of said pinned layer and said free layer including a thin-film insertion layer, and

said thin-film insertion layer being a binary alloy containing a quantity of iron (Fe) not less than 50 atomic % as the major component thereof, or a ternary alloy containing a quantity of iron (Fe) not less than 25 atomic % as the major component thereof, and said alloy having a body-centered cubic crystal structure.

9. The magnetic reproducing apparatus according to claim 8, wherein said alloy additionally contains a quantity of at least one kind of element selected from the group consisting of copper (Cu), silver (Ag), and gold (Au) not less than 0.1 atomic % and not exceeding 20 atomic %.

10. The magnetic reproducing apparatus according to claim 8, wherein a back insertion layer made of copper (Cu), gold (Au), silver (Ag), or an alloy combining at least two kinds of these metals is provided adjacent to an interface of said free layer not in contact with said nonmagnetic intermediate layer.