Magnetoresistive element having a magnetic layer including O

1. A magnetoresistive element comprising:

a first magnetic layer including O and one of Co, Fe, Ni and Mn;

a second magnetic layer;

a nonmagnetic layer between the first and second magnetic layers;

a first electrode electrically connected to the first magnetic layer;

a second electrode electrically connected to the second magnetic layer; and

a resistive layer including N between the first magnetic layer and the first electrode.

2. The element of claim 1 , wherein an amount of O in an area adjacent to the first electrode is greater than an amount of O in an area adjacent to the nonmagnetic layer.

3. The element of claim 1 , wherein the first magnetic layer is a storage layer having a variable magnetization, and the second magnetic layer is a reference layer having an invariable magnetization.

4. The element of claim 1 , wherein the resistive layer is a nitride, and R 1 >R 3 >R 2 is satisfied, where R 1 is a resistance of the nonmagnetic layer, R 2 is a resistance of the first magnetic layer, and R 3 is a resistance of the resistive layer.

5. The element of claim 4 , wherein R 3 >R P /MR is satisfied, where R P is a resistance of the element in a low-resistance state, and MR is a magnetoresistive ratio of the element.

6. The element of claim 4 , wherein the element has a size of 90 nm or less in a direction perpendicular to a direction in which the first magnetic layer, the nonmagnetic layer, and the second magnetic layer are stacked.

7. The element of claim 4 , wherein electrons flow from the first magnetic layer to the second magnetic layer in a read operation.

8. The element of claim 4 , wherein the resistive layer comprises the nitride of one of Al, Be, Mg, Ca, Sr, Ba, Sc, Y, La, Zr, and Hf.

9. The element of claim 4 , wherein the resistive layer comprises a first nitride and a second nitride between the storage layer and the first nitride, and the second nitride has a resistance higher than a resistance of the first nitride.

10. The element of claim 1 , wherein the first magnetic layer is provided on the resistive layer, the nonmagnetic layer is provided on the first magnetic layer, and the second magnetic layer is provided on the nonmagnetic layer.

11. A magnetoresistive element comprising:

a first magnetic layer;

a second magnetic layer;

a nonmagnetic layer between the first and second magnetic layers;

a first electrode electrically connected to the first magnetic layer;

a second electrode electrically connected to the second magnetic layer; and

a resistive layer between the first magnetic layer and the first electrode,

wherein R x1 >R y1 is satisfied when a relative magnetization direction between the first and second magnetic layers is constant, where R x1 is a resistance of the element when a potential of the first electrode is lower than a potential of the second electrode, and R y1 is the resistance of the element when the potential of the second electrode is lower than the potential of the first electrode.

12. The element of claim 11 , wherein the first magnetic layer is a storage layer having a variable magnetization, and the second magnetic layer is a reference layer having a constant magnetization.

13. The element of claim 11 , wherein the resistive layer comprises a nitride, and R 1 >R 3 >R 2 is satisfied, where R 1 is a resistance of the nonmagnetic layer, R 2 is a resistance of the first magnetic layer, and R 3 is a resistance of the resistive layer.

14. The element of claim 11 , wherein R 3 >R P /MR is satisfied, where R P is the resistance of the element in a low-resistance state, and MR is a magnetoresistive ratio of the element.

15. The element of claim 11 , wherein the element has a size of 90 nm or less in a direction perpendicular to a direction in which the first magnetic layer, the nonmagnetic layer, and the second magnetic layer are stacked.

16. The element of claim 11 , wherein R x >R y is satisfied, where R x is a difference between R x1 and R x2 when the potential of the first electrode is lower than the potential of the second electrode, R y is a difference between R y1 and R y2 when the potential of the second electrode is lower than the potential of the first electrode, each of R x1 and R y1 is a resistance of the element in an anti-parallel state, and each of R x2 and R y2 is a resistance of the element in a parallel state, and

wherein electrons flow from the first magnetic layer to the second magnetic layer in a read operation.

17. The element of claim 11 , wherein the resistive layer comprises a nitride of one of Al, Be, Mg, Ca, Sr, Ba, Sc, Y, La, Zr, and Hf.

18. The element of claim 11 , wherein the resistive layer comprises a first nitride and a second nitride between the first magnetic layer and the first nitride, and the second nitride has a resistance higher than a resistance of the first nitride.

19. The element of claim 11 , wherein the first magnetic layer is provided on the resistive layer, the nonmagnetic layer is provided on the first magnetic layer, and the second magnetic layer is provided on the nonmagnetic layer.