Magnetoresistive element

Abstract

To provide a magnetoresistance effect element with a large MR ratio.SOLUTION: A magnetoresistance effect element comprises a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer. The first ferromagnetic layer includes a first layer and a second layer. The first layer is arranged closer to the non-magnetic layer than the second layer. The first layer contains a heusler alloy which is at least partially crystallized. The second layer includes a ferromagnetic body which is at least partially crystallized, unlike the heusler alloy. The first layer and the second layer include a first atom added. The first atom is one selected from the group consisting of Mg, Al, Cr, Mn, Ni, Cu, Zn, Pd, Cd, In, Sn, Sb, Pt, Au, and Bi.SELECTED DRAWING: Figure 1

Claims

1. It comprises a first ferromagnetic layer, a second ferromagnetic layer, and a non-magnetic layer. The first ferromagnetic layer comprises a first layer and a second layer. The first layer is closer to the non-magnetic layer than the second layer, The first layer has a Heusler alloy containing at least a portion of crystallized Co, Unlike the Heusler alloy, the second layer has at least a portion of a crystalline ferromagnetic material. The first layer and the second layer each have the added first atom, The first atom is selected from the group consisting of Mg, Al, Cr, Mn, Ni, Cu, Zn, Pd, Cd, In, Sn, Sb, Pt, Au, and Bi. The ferromagnetic material is represented as Co x Fe 1-x -A, x is between 0 and 1, and A is the first atom. The first ferromagnetic layer further comprises a fifth layer, The first layer and the fifth layer are separated by the second layer, The fifth layer is a magnetoresistive element having the Heusler alloy.

2. The aforementioned second ferromagnetic layer has a third layer and a fourth layer, The third layer is closer to the non-magnetic layer than the fourth layer, The third layer has a Heusler alloy containing at least a portion of crystallized Co, Unlike the Heusler alloy, the fourth layer has at least a portion of a crystalline ferromagnetic material. The magnetoresistive element according to claim 1, wherein the third layer and the fourth layer have the first atom.

3. The magnetoresistive element according to claim 1, wherein the crystal structure of the ferromagnetic material is a bcc structure or an fcc structure.

4. The first layer and the second layer are adjacent to each other. The first layer and the second layer are grid-matched, The magnetoresistive element according to claim 1, wherein, with respect to the lattice constant of the second layer, the lattice constant of the first layer is 95% or more and 105% or less of the lattice constant of the second layer.

5. The magnetoresistive element according to claim 1, wherein the first surface of the first layer on the non-magnetic layer side has a lower concentration of the first atoms than the second surface on the opposite side of the first surface.

6. The magnetoresistive element according to claim 1, wherein the concentration of the first atom in the first layer is lower than the concentration of the first atom in the second layer.

7. The crystal structure of the aforementioned Heusler alloy is L2 １ A magnetoresistive element according to claim 1, wherein the element has a B2 structure or a B2 structure.

8. The aforementioned Heusler alloy has the compositional formula Co ２ Y α Z β It is written as, The aforementioned Y is one or more elements selected from the group consisting of Fe, Mn, and Cr. The aforementioned Z is one or more elements selected from the group consisting of Si, Al, Ga, and Ge. A magnetoresistive element according to claim 1, satisfying α + β > 2.

9. The magnetoresistive element according to claim 1, wherein the first atom substitutes for a part of the crystal structure of the Heusler alloy.

10. The magnetoresistive element according to claim 1, further comprising a NiAl alloy layer in at least one of the spaces between the first ferromagnetic layer and the non-magnetic layer, and between the second ferromagnetic layer and the non-magnetic layer.

11. The magnetoresistive element according to claim 10, wherein the thickness of the NiAl alloy layer is 0.63 nm or less.

12. The magnetoresistive element according to claim 1, wherein the non-magnetic layer is a metal or alloy containing any element selected from the group consisting of Cu, Au, Ag, Al, and Cr.

13. It further has a substrate, The substrate is a base on which the first ferromagnetic layer, the second ferromagnetic layer, and the non-magnetic layer are laminated. The magnetoresistive element according to claim 1, wherein the substrate is amorphous.

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