Magnetoresistive effect element, magnetic head, sensor, high-frequency filter, and oscillator
A nonmagnetic spacer layer in a magnetoresistive effect element includes a nonmagnetic metal layer that is formed of Ag and at least one of a first insertion layer that is disposed on a bottom surface of the nonmagnetic metal layer and a second insertion layer that is disposed on a top surface of the nonmagnetic metal layer. The first insertion layer and the second insertion layer include an Fe alloy that is expressed by Fe γ X 1-γ . Here, X denotes one or more elements selected from a group consisting of O, Al, Si, Ga, Mo, Ag, and Au, and γ satisfies 0<γ<1.
1. A magnetoresistive effect element comprising:
a first ferromagnetic layer;
a second ferromagnetic layer; and
a spacer layer that is disposed between the first ferromagnetic layer and the second ferromagnetic layer,
wherein the spacer layer includes:
a nonmagnetic metal layer including Ag, and
at least one of
a first insertion layer that is disposed on a bottom surface of the nonmagnetic metal layer and
a second insertion layer that is disposed on a top surface of the nonmagnetic metal layer, and
wherein the first insertion layer and the second insertion layer include an Fe alloy that is expressed by General Formula (1):
Fe γ X 1-γ (1),
where X denotes one or more elements selected from a group consisting of O, Al, Si, Ga, Mo, Ag, and Au, and
γ satisfies 0<γ<1,
wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a Heusler alloy that is expressed by General formula (2):
Co 2 L α M β (2),
where L denotes one or more elements selected from a group consisting of Mn and Fe,
M denotes one or more elements selected from a group consisting of Si, Al, Ga, and Ge,
0.7≤α≤1.6, and
0.65≤β≤1.35,
wherein α and β in General formula (2) satisfy 2<α+β.
2. The magnetoresistive effect element according to claim 1 , wherein
γ in General Formula (1) satisfies 0.6≤γ≤0.9.
3. The magnetoresistive effect element according to claim 2 , wherein X in General formula (1) is one or more elements selected from a group consisting of Al, Si, and Ga.
4. The magnetoresistive effect element according to claim 3 , wherein α and β in General formula (2) satisfy:
0.85≤α≤1.55, and
0.75≤β≤1.25.
5. The magnetoresistive effect element according to claim 3 , wherein 1≤α.
6. The magnetoresistive effect element according to claim 5 ,
wherein 0.2 nm≤t 1 ≤10 nm is satisfied where t 1 denotes a thickness of the first insertion layer, and
wherein 0.2 nm≤t 2 ≤10 nm is satisfied where t 2 denotes a thickness of the second insertion layer.
7. The magnetoresistive effect element according to claim 1 , wherein α and β in General formula (2) satisfy:
0.85≤α≤1.55, and
0.75≈β≤1.25.
8. The magnetoresistive effect element according to claim 1 ,
wherein 0.2 nm≤t 1 ≤10 nm is satisfied where t 1 denotes a thickness of the first insertion layer, and
wherein 0.2 nm≤t 2 ≤10 nm is satisfied where t 2 denotes a thickness of the second insertion layer.
9. The magnetoresistive effect element according to claim 1 ,
wherein α and β in General formula (2) further satisfy
α+β2.75.
10. A magnetic head comprising the magnetoresistive effect element according to claim 1 .
11. A sensor comprising the magnetoresistive effect element according to claim 1 .
12. A high-frequency filter comprising the magnetoresistive effect element according to claim 1 .
13. An oscillator comprising the magnetoresistive effect element according to claim 1 .
14. A magnetoresistive effect element comprising:
a first ferromagnetic layer;
a second ferromagnetic layer; and
a spacer layer that is disposed between the first ferromagnetic layer and the second ferromagnetic layer,
wherein the spacer layer includes:
a nonmagnetic metal layer, and at least one of
a first insertion layer that is disposed on a bottom surface of the nonmagnetic metal layer and
a second insertion layer that is disposed on a top surface of the nonmagnetic metal layer,
wherein the first insertion layer and the second insertion layer include an Fe alloy that is expressed by General Formula (1):
Fe γ X 1-γ (1),
where X denotes one or more elements selected from a group consisting of Al, Ga and Ag, and
γ satisfies 0.6≤γ≤0.9,
wherein the first insertion layer is continued from one side to the other side of the magnetoresistive effect element in a transverse direction of the magnetoresistive effect element,
wherein the second insertion layer is continued from one side to the other side of the magnetoresistive effect element in a transverse direction of the magnetoresistive effect element,
wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a Heusler alloy that is expressed by General formula (2):
Co 2 L α M β (2)
where L denotes one or more elements selected from a group consisting of Mn and Fe,
M denotes one or more elements selected from a group consisting of Si, Al, Ga, and Ge,
1≤α,
0.65≤β≤1.35, and
2≤α+β.
15. The magnetoresistive effect element according to claim 14 ,
wherein 0.2 nm≤t 1 ≤10 nm is satisfied where t 1 denotes a thickness of the first insertion layer, and
wherein 0.2 nm≤t 2 ≤10 nm is satisfied where t 2 denotes a thickness of the second insertion layer.
16. The magnetoresistive effect element according to claim 14 ,
wherein α and β in General formula (2) further satisfy
α+β≤2.75.
17. A magnetic head comprising the magnetoresistive effect element according to claim 14 .
18. A sensor comprising the magnetoresistive effect element according to claim 14 .
19. A high-frequency filter comprising the magnetoresistive effect element according to claim 14 .
20. An oscillator comprising the magnetoresistive effect element according to claim 14 .
21. A magnetoresistive effect element comprising:
a first ferromagnetic layer;
a second ferromagnetic layer; and
a spacer layer that is disposed between the first: ferromagnetic layer and the second ferromagnetic layer,
wherein the spacer layer includes:
a nonmagnetic metal layer, and
at least one of
a first insertion layer that is disposed on a bottom surface of the nonmagnetic metal layer and
a second insertion layer that is disposed on a top surface of the nonmagnetic metal layer, and
wherein the first insertion layer and the second insertion layer include an Fe alloy that is expressed by General Formula (1):
Fe γ X 1-γ (1),
where X denotes one or more elements selected from a group consisting of Mo and Au, and
γ satisfies 0.6≤γ≤0.9, and
wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer includes a Heusler alloy that is expressed by General formula (2):
Co 2 LαMβ (2),
where L denotes one or more elements selected from a group consisting of Mn and Fe,
M denotes one or more elements selected from a group consisting of Si, Al, Ga, and Ge,
0.7≤α≤1.6,
0.65≤β≤1.35, and
2<α+β.
22. The magnetoresistive effect element according to claim 21 , wherein 1≤α.
23. The magnetoresistive effect element according to claim 22 ,
wherein 0.2 nm≤t 1 ≤10 nm is satisfied where t 1 denotes a thickness of the first insertion layer, and
wherein 0.2 nm≤t 2 ≤10 nm is satisfied where t 2 denotes a thickness of the second insertion layer.
24. The magnetoresistive effect element according to claim 21 ,
wherein α and β in General formula (2) further satisfy
α+β≤2.75.
25. A magnetic head comprising the magnetoresistive effect element according to claim 21 .
26. A sensor comprising the magnetoresistive effect element according to claim 21 .
27. A high-frequency filter comprising the magnetoresistive effect element according to claim 21 .
28. An oscillator comprising the magnetoresistive of according to claim 21 .