Granted Patent B2

US 12,437,779 · App. 18/765,906 · Granted Oct 7, 2025

Inventors: Yuji Nakagawa (Kawasaki, JP); Naoyuki Narita (Funabashi, JP); Masayuki Takagishi (Kunitachi, JP); Tomoyuki Maeda (Kawasaki, JP); Tazumi Nagasawa (Yokohama, JP)

Assignees: KABUSHIKI KAISHA TOSHIBA; TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION

G11B5/21G11B5/1278G11B5/3146

Abstract

Claims (50)

1. A magnetic head, comprising:

a first magnetic pole;

a second magnetic pole; and

a stacked body provided between the first magnetic pole and the second magnetic pole, the stacked body including

a first magnetic layer,

a second magnetic layer provided between the first magnetic pole and the first magnetic layer,

a third magnetic layer provided between the first magnetic pole and the second magnetic layer,

a first nonmagnetic layer provided between the first magnetic layer and the second magnetic pole,

a second nonmagnetic layer provided between the second magnetic layer and the first magnetic layer, and

a third nonmagnetic layer provided between the third magnetic layer and the second magnetic layer,

the first magnetic layer including (Fe 100-x Co x ) 100-y (10 atomic % ≤x≤50 atomic %, 10 atomic % ≤y≤90 atomic %), a second element E including at least one selected from the group consisting of Cr, V, Mn, Ti and Sc,

the second magnetic layer including at least one of Fe, Co, or Ni, the second magnetic layer not including the second element, or a concentration of the second element in the second magnetic layer being less than a concentration of the second element in the first magnetic layer,

the third magnetic layer including (Fe 100-p Co p ) 100-q EX q (10 atomic % ≤p≤50 atomic %, 10 atomic % ≤q≤90 atomic %), a fourth element EX including at least one selected from the group consisting of Cr, V, Mn, Ti and Sc,

the second magnetic layer not including the fourth element, or a concentration of the fourth element in the second magnetic layer being less than a concentration of the fourth element in the third magnetic layer,

the first nonmagnetic layer including at least one selected from the group consisting of Cu, Ag, Au, Al, and Cr,

the second nonmagnetic layer including at least one selected from the group consisting of Cu, Ag, Au, Al, and Cr, and

the third nonmagnetic layer including at least one selected from the group consisting of Cu, Ag, Au, Al, and Cr.

2. The head according to claim 1 , wherein

the composition ratio x is not less than 25 atomic % and not more than 35 atomic %, and

the composition ratio p is not less than 25 atomic % and not more than 35 atomic %.

3. The head according to claim 2 , wherein

the composition ratio y is not less than 10 atomic % and not more than 30 atomic %, and

the composition ratio q is not less than 10 atomic % and not more than 30 atomic %.

4. The head according to claim 1 , wherein the second nonmagnetic layer and the third nonmagnetic layer include Cr.

5. The head according to claim 1 , wherein

the first nonmagnetic layer contacts the first magnetic layer and the second magnetic pole,

the second nonmagnetic layer contacts the second magnetic layer and the first magnetic layer, and

the third nonmagnetic layer contacts the third magnetic layer and the second magnetic layer.

6. The head according to claim 1 , wherein the first magnetic pole contacts the third magnetic layer.

7. The head according claim 1 , wherein

the stacked body further includes a fourth nonmagnetic layer,

the fourth nonmagnetic layer is located between the first magnetic pole and the third magnetic layer, and

the fourth nonmagnetic layer includes at least one selected from the group consisting of Cu, Ag, Au, Al, and Cr.

8. The head according to claim 7 , wherein the fourth nonmagnetic layer contacts the first magnetic pole and the third magnetic layer.

9. The head according to claim 7 , wherein a thickness of the fourth nonmagnetic layer is not less than 1 nm and not more than 5 nm.

10. The head according to claim 1 , wherein a second current has an orientation from the first magnetic layer toward the second magnetic layer.

11. The head according claim 1 , wherein a thickness of the first nonmagnetic layer is not less than 1 nm and not more than 5 nm.

12. The head according claim 1 , wherein a thickness of the second nonmagnetic layer is not less than 1 nm and not more than 5 nm.

13. The head according to claim 1 , wherein a thickness of the third nonmagnetic layer is not less than 1 nm and not more than 5 nm.

14. The head according to claim 1 , wherein a thickness of the first magnetic layer is not less than 2 nm and not more than 8 nm.

15. The head according to claim 1 , wherein a thickness of the second magnetic layer is not less than 2 nm and not more than 5 nm.

16. The head according to claim 1 , wherein a thickness of the third magnetic layer is not less than 2 nm and not more than 5 nm.

17. A magnetic recording device, comprising:

the magnetic head according to claim 1 ;

a magnetic recording medium; and

an electrical circuit,

an electrical resistance of the stacked body being a first resistance when a current flowing in the stacked body is a first current,

the electrical resistance of the stacked body being a second resistance when the current flowing in the stacked body is a second current, the second current being greater than the first current, the second resistance being greater than the first resistance,

the electrical resistance of the stacked body oscillating when the current flowing in the stacked body is a third current, the third current being between the first current and the second current, and

the electrical circuit being configured to supply the second current to the stacked body in a recording operation of using the magnetic head to record information in the magnetic recording medium.

Priority Claims (1)

Continuity (3)

References Cited (39)