Magnetoresistive effect element and magnetic memory

1. A magnetoresistive effect element comprising:

a recording layer comprising ferromagnetic material with perpendicular magnetic anisotropy to a film surface and a variable orientation of magnetization;

a reference layer comprising ferromagnetic material with perpendicular magnetic anisotropy to a film surface and an invariable orientation of magnetization;

a nonmagnetic layer between the recording layer and the reference layer;

a first underlayer on a side of the recoding layer opposite to a side on which the nonmagnetic layer is provided; and

a second underlayer between the recording layer and the first underlayer,

wherein

the second underlayer is a Pd film including a concentration of 3×10 15 atms/cm 2 .

2. The magnetoresistive effect element according to claim 1 , wherein

the recording layer comprises:

a first magnetic layer including at least two of Co, Fe and B; and

an insertion film selected from a group including Ta, Nb, Mo and W, and

wherein the first magnetic layer is arranged on a side of the nonmagnetic layer, and the insertion layer is arranged on a side of the second underlayer.

3. The magnetoresistive effect element according to claim 2 , wherein

the recording layer further comprises a second magnetic layer including at least one of Co and Tb, and

the second magnetic layer is provided between the second underlayer and the insertion film.

4. The magnetoresistive effect element according to claim 3 , wherein

when the second magnetic layer is a Co film, the Co film comprises a distance between atomic layers equal to or more than 1.35 Å and equal to or less than 1.55 Å in an in-film surface direction.

5. The magnetoresistive effect element according to claim 2 , wherein

the insertion film is oriented toward a bcc {001} surface.

6. The magnetoresistive effect element according to claim 2 , wherein

the first magnetic layer is oriented toward a bcc {100} surface.

7. The magnetoresistive effect element according to claim 2 , wherein

the first magnetic layer includes Co and Fe, and

a concentration of the Fe in the first magnetic layer is higher than a concentration of the Co in the first magnetic layer.

8. The magnetoresistive effect element according to claim 1 , wherein

the recording layer comprises:

a first magnetic layer including at least two of Co, Fe and B;

an insertion film selected from a group including Ta, Nb, Mo and W;

a second magnetic layer including at least one of Co and Tb; and

a third magnetic layer including at least two of Co, Fe and B,

wherein the first magnetic layer is arranged on the side of the nonmagnetic layer,

the second magnetic layer is arranged on a side of the second underlayer,

the insertion film is arranged on a side of the first magnetic layer between the first magnetic layer and the second magnetic layer, and

the third magnetic layer is arranged on a side of the second magnetic layer between the first magnetic layer and the second magnetic layer.

9. The magnetoresistive effect element according to claim 8 , wherein

when the second magnetic layer is a Co film, the Co film comprises a distance between atomic layers equal to or more than 1.35 Å and equal to or less than 1.55 Å in an in-film surface direction.

10. The magnetoresistive effect element according to claim 8 , wherein

the insertion film is oriented toward a bcc {001} surface.

11. The magnetoresistive effect element according to claim 1 , wherein

the recording layer comprises:

a first magnetic layer including at least two of Co, Fe and B; and

a second magnetic layer including at least one of Co and Fe,

wherein the first magnetic layer is arranged on a side of the nonmagnetic layer, and the second magnetic layer is arranged on a side of the second underlayer.

12. The magnetoresistive effect element according to claim 11 , wherein

when the first magnetic layer is a CoFeB film and the second magnetic layer is CoFe, a concentration of Fe in the first magnetic layer is higher than a concentration of Fe in the second magnetic layer.

13. The magnetoresistive effect element according to claim 11 , wherein

when the second magnetic layer is a Co film, the Co film comprises a distance between atomic layers equal to or more than 1.35 Å and equal to or less than 1.55 Å in an in-film surface direction.

14. The magnetoresistive effect element according to claim 1 , wherein

the recording layer comprises:

a first magnetic layer on a side of the nonmagnetic layer; and

a second magnetic layer on a side of the second underlayer,

wherein the first magnetic layer is (Co x Fe 100-x ) 100-z B z (x≦75 atomic % and 0≦z≦30 atomic %), and the second magnetic film is (Co w Fe 100-w ) 100-z B z (0≦z≦30 atomic % and x<w).

15. The magnetoresistive effect element according to claim 1 , wherein

the first underlayer comprises an atom dense surface.

16. The magnetoresistive effect element according to claim 1 , wherein

the first underlayer is selected from a group including an Ir, Pt, Ru, AlN and NbN.

17. A magnetic memory comprising:

a memory cell comprising the magnetoresistive effect element according to claim 1 .

18. The magnetic memory according to claim 17 , wherein

the recording layer comprises:

a first magnetic layer including at least two of Co, Fe and B; and

at least one insertion film selected from a group including Ta, Nb, Mo and W,

wherein the first magnetic layer is arranged on a side of the first nonmagnetic layer, and the insertion layer is arranged on a side of the second underlayer.

19. The magnetic memory according to claim 18 , wherein

the insertion film is oriented toward a bcc {001} surface.

20. The magnetic memory according to claim 17 , wherein

the first underlayer comprises an atom dense surface.