Magnetoresistive element and magnetic memory

1. A magnetoresistive element comprising:

a first magnetic layer;

an MgFeO layer; and

a second magnetic layer stacked in a first direction, the MgFeO layer disposed between the first and second magnetic layers; wherein

Fe of the MgFeO layer is included at least in a central portion of the MgFeO layer in the first direction, and

the MgFeO layer contains at least one element selected from a group consisting of Ti, V, Mn, and Cu.

2. The element according to claim 1 ,

wherein at least one of the first and second magnetic layers includes Fe.

3. The element according to claim 1 ,

wherein at least one of the first and second magnetic layers includes a same metal element as a metal element contained in the MgFeO layer.

4. The element according to claim 1 ,

wherein at least one of a concentration of Fe in a region between the first magnetic layer and the MgFeO layer and a concentration of Fe in a region between the second magnetic layer and the MgFeO layer is higher than a concentration of Fe at the central portion of the MgFeO layer.

5. The element according to claim 1 ,

wherein the MgFeO layer includes at least one of a fine crystal phase and an amorphous phase.

6. The element according to claim 1 ,

wherein the MgFeO layer further includes boron.

7. A magnetic memory comprising a memory cell including the magnetoresistive element according to claim 1 .

8. A magnetoresistive element comprising:

a first magnetic layer;

an MgFeO layer; and

a second magnetic layer stacked in a first direction, the MgFeO layer disposed between the first and second magnetic layers; wherein

Fe of the MgFeO layer is included at least in a central portion of the MgFeO layer in the first direction, and

the MgFeO layer contains boron.

9. The element according to claim 8 ,

wherein at least one of the first and second magnetic layers includes Fe.

10. The element according to claim 8 , wherein at least one of a concentration of Fe in a region between the first magnetic layer and the MgFeO layer and a concentration of Fe in a region between the second magnetic layer and the MgFeO layer is higher than a concentration of Fe at the central portion of the MgFeO layer.

11. The element according to claim 8 ,

wherein the MgFeO layer includes at least one of a fine crystal phase and an amorphous phase.

12. A magnetic memory comprising a memory cell including the magnetoresistive element according to claim 8 .

13. A magnetoresistive element comprising:

a first magnetic layer having a variable magnetization direction;

a second magnetic layer having an invariable magnetization direction; and

a tunnel barrier layer provided between the first magnetic layer and the second magnetic layer and including an MgFeO layer, wherein

Fe of the MgFeO layer is included at least in a central portion of the MgFeO layer in a thickness direction,

at least one of a concentration of Fe in a region between the first magnetic layer and the MgFeO layer and a concentration of Fe in a region between the second magnetic layer and the MgFeO layer is higher than a concentration of Fe at the central portion of the MgFeO layer, and

the MgFeO layer contains at least one element selected from a group consisting of Ti, V, Mn, and Cu.

14. A magnetoresistive element comprising:

a first magnetic layer having a variable magnetization direction;

a second magnetic layer having an invariable magnetization direction; and

a tunnel barrier layer provided between the first magnetic layer and the second magnetic layer and including an MgFeO layer, wherein

Fe of the MgFeO layer is included at least in a central portion of the MgFeO layer in a thickness direction,

at least one of a concentration of Fe in a region between the first magnetic layer and the MgFeO layer and a concentration of Fe in a region between the second magnetic layer and the MgFeO layer is higher than a concentration of Fe at the central portion of the MgFeO layer, and

the MgFeO layer contains boron.