Magnetoresistive element, magnetic head, magnetic recording apparatus, and magnetic memory

• US 20060050444A1
• Filed: 09/01/2005
• Published: 03/09/2006
• Est. Priority Date: 09/03/2004
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Fukuzawa, Hideaki, Yuasa, Hiromi, Iwasaki, Hitoshi
• Granted Patent: US 8,213,129 B2
• Time in Patent Office: Days
• US Class Current: 360/324
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures

Abstract

A magnetoresistive element includes at least three metallic magnetic layers, at least two connection layers provided between the at least three metallic magnetic layers, each having an insulating layer and current confined paths including a metallic magnetic material penetrating the insulating layer, and electrodes which supply a current perpendicularly to a plane of a stacked film of the metallic magnetic layers and the connection layers.

Claims

1. A magnetoresistive element comprising:

at least three metallic magnetic layers;

at least two connection layers provided between the at least three metallic magnetic layers, each having an insulating layer and current confined paths comprising a metallic magnetic material penetrating the insulating layer; and

electrodes which supply a current perpendicularly to a plane of a stacked film of the metallic magnetic layers and the connection layers.

2. The magnetoresistive element according to claim 1, wherein a lowermost or uppermost metallic magnetic layer of the at least three metallic magnetic layers has magnetization pinned in a direction, the lowermost metallic magnetic layer and the uppermost metallic magnetic layer are magnetically coupled through the at least two connection layers and one or more intermediate metallic magnetic layers sandwiched between the lowermost and uppermost metallic magnetic layers, and the magnetization direction of the intermediate metallic magnetic layer is twisted such that the magnetization direction of the lowermost metallic magnetic layer is orthogonal to that of the uppermost metallic magnetic layer at zero external field.

3. The magnetoresistive element according to claim 1, further comprising a nonmagnetic metal layer at least one interface between the connection layers and the metallic magnetic layers.

4. The magnetoresistive element according to claim 1, wherein the connection layer has a thickness in a range between 0.5 nm or more and 2.5 nm or less, the insulating layer is formed of an oxide or nitride of Al, Si, Ti, Hf, Zr, Mo, or Ta, and the current confined paths are formed of a metallic magnetic material containing Co, Fe, or Ni.

5. The magnetoresistive element according to claim 1, wherein the connection layer has a thickness in a range between 0.5 nm or more and 2.5 nm or less, the insulating layer is formed of an oxide containing Fe, and the current confined paths are formed of a metallic magnetic material containing Co, Fe, or Ni.

6. The magnetoresistive element according to claim 1, wherein the current confined paths have a size in a range between 0.5 nm or more and 10 nm or less, and an area ratio of the current confined paths in an area of a plane of the connection layer is in a range between 1 to 30%.

7. The magnetoresistive element according to claim 1, wherein the current confined paths have a stacked structure of a metallic magnetic material and a nonmagnetic metal material.

8. The magnetoresistive element according to claim 7, wherein the current confined paths include a plurality of layers of at least one of the magnetic metallic material and nonmagnetic metal material.

9. The magnetoresistive element according to claim 1, wherein nonmagnetic metal layers are formed between both surfaces of the connection layer and an upper and lower metallic magnetic layers thereof.

10. The magnetoresistive element according to claim 1, wherein nonmagnetic metal layers are formed between both surfaces of the connection layer and an upper and lower metallic magnetic layers thereof, and the current confined paths in the connection layer have a stacked structure of a metallic magnetic material and a nonmagnetic metal material.

15. A magnetic recording apparatus comprising a magnetic recording media and the magnetic head according to claim 1.

16. A magnetic memory comprising the magnetoresistive element according to claim 1.

11. A magnetoresistive element comprising:

at least three metallic magnetic layers;

at least two nonmagnetic metal layers provided between the at least three metallic magnetic layers; and

electrodes which supply a current perpendicularly to a plane of a stacked film of the metallic magnetic layers and the nonmagnetic metal layers.

12. The magnetoresistive element according to claim 11, wherein a lowermost or uppermost metallic magnetic layer of the at least three metallic magnetic layers has magnetization pinned in a direction, the lowermost metallic magnetic layer and the uppermost metallic magnetic layer are magnetically coupled through the at least two nonmagnetic metal layers and one or more intermediate metallic magnetic layers sandwiched between the lowermost and uppermost metallic magnetic layers, and the magnetization direction of the intermediate metallic magnetic layer is twisted such that the magnetization direction of the lowermost metallic magnetic layer is orthogonal to that of the. uppermost metallic magnetic layer at zero external field.

17. A magnetic recording apparatus comprising a magnetic recording media and the magnetic head according to claim 11.

18. A magnetic memory comprising the magnetoresistive element according to claim 11.

13. A magnetoresistive element comprising:

at least three metallic magnetic layers;

at least two layers provided between the at least three metallic magnetic layers, each of the at least is two layers being selected from the group consisting of a connection layer having an insulating layer and current confined paths comprising a metallic magnetic material penetrating the insulating layer, a nonmagnetic metal layer and a stack of the connection layer and the nonmagnetic metal layer; and

electrodes which supply a current perpendicularly to a plane of a stacked film of the metallic magnetic layers and the connection layers.

14. The magnetoresistive element according to claim 13, wherein a lowermost or uppermost metallic magnetic layer of the at least three metallic magnetic layers has magnetization pinned in a direction, the lowermost metallic magnetic layer and the uppermost metallic magnetic layer are magnetically coupled through the at least two layers, each of at least two layers being selected from the group consisting of a connection layer having an insulating layer and current confined paths comprising a metallic magnetic material penetrating the insulating layer, a nonmagnetic metal layer and a stack of the connection layer and the nonmagnetic metal layer, and one or more intermediate metallic magnetic layers sandwiched between the lowermost and uppermost metallic magnetic layers, and the magnetization direction of the intermediate metallic magnetic layer is twisted such that the magnetization direction of the lowermost metallic magnetic layer is orthogonal to that of the uppermost metallic magnetic layer at zero external field.

19. A magnetic recording apparatus comprising a magnetic recording media and the magnetic head according to claim 13.

20. A magnetic memory comprising the magnetoresistive element according to claim 13.