Magnetoresistance effect element including at least one Heusler alloy layer and at least one discontinuous non-magnetic layer

1. A magnetoresistance effect element comprising:

a first ferromagnetic layer;

a second ferromagnetic layer;

a first non-magnetic layer; and

a second non-magnetic layer, wherein

the first ferromagnetic layer and the second ferromagnetic layer are formed so that at least one of them includes a Heusler alloy layer,

the first non-magnetic layer is provided between the first ferromagnetic layer and the second ferromagnetic layer,

the second non-magnetic layer is in contact with any surface of the Heusler alloy layer and has a discontinuous portion with respect to a lamination surface, and

the second non-magnetic layer is made of a material different from that of the first non-magnetic layer and is a (001)-oriented oxide containing Mg.

2. The magnetoresistance effect element according to claim 1 ,

wherein an area ratio occupied by the second non-magnetic layer in a plan view from a lamination direction is 10% or more and 80% or less.

3. The magnetoresistance effect element according to claim 2 ,

wherein an area ratio occupied by the second non-magnetic layer in the plan view from the lamination direction is 20% or more and 60% or less.

4. The magnetoresistance effect element according to claim 1 ,

wherein the Heusler alloy layer is mainly oriented in a (001) direction.

5. The magnetoresistance effect element according to claim 1 ,

wherein the second non-magnetic layer contains one or more element selected from a group consisting of Al, Ga, Ti, and Ni.

6. The magnetoresistance effect element according to claim 1 ,

wherein the Heusler alloy layer is represented by a composition formula Co 2 Y α Z β ,

wherein the Y is one or more elements selected from a group consisting of Fe, Mn, and Cr,

wherein the Z is one or more elements selected from a group consisting of Si, Al, Ga, and Ge, and

wherein α+β>2 is satisfied.

7. The magnetoresistance effect element according to claim 6 ,

wherein the Y is Fe and the Z is Ga and Ge.

8. The magnetoresistance effect element according to claim 1 ,

wherein the Heusler alloy layer is represented by a composition formula Co 2 Fe α Ga β1 Ge β2 , and

wherein α+β1+β2≥2.3, α<β1+β2, 0.5<α<1.9, 0.1≤β1, and 0.1≤β2 are satisfied.

9. The magnetoresistance effect element according to claim 1 ,

wherein the first non-magnetic layer is a metal or alloy containing one or more element selected from a group consisting of Cu, Au, Ag, Al, and Cr.

10. The magnetoresistance effect element according to claim 1 , further comprising:

a substrate,

wherein the substrate is an underlying layer on which the first ferromagnetic layer, the second ferromagnetic layer, the first non-magnetic layer, and the second non-magnetic layer are laminated, and

wherein the substrate is amorphous.