Tunnel magnetoresistance effect device and magnetic device using same

1. A tunnel magnetoresistance effect device comprising:

a structure comprising a fixed magnetic layer having a ferromagnetic layer and a free magnetic layer that is laminated through an insulating barrier layer, wherein:

the ferromagnetic layer and an antiferromagnetic layer laminated on the ferromagnetic layer constitute an exchange coupling film;

the antiferromagnetic layer includes an X(Cr—Mn) layer containing one or two or more elements X selected from the group consisting of the platinum group elements and Ni, and also containing Mn and Cr;

the X(Cr—Mn) layer has a first region relatively near the ferromagnetic layer, and a second region relatively far away from the ferromagnetic layer; and

the content of Mn in the first region is higher than that in the second region;

wherein in the exchange-coupling film, a normalized exchange-coupling magnetic field obtained by dividing an exchange-coupling magnetic field measured at 422° C. by an exchange-coupling magnetic field measured at 22° C. is 0.34 or greater.

2. The tunnel magnetoresistance effect device according to claim 1 , wherein the first region is in contact with the ferromagnetic layer.

3. The tunnel magnetoresistance effect device according to claim 1 , wherein the first region has a portion having a Mn/Cr ratio of 0.3 or more, which is the ratio of the Mn content to the Cr content.

4. The tunnel magnetoresistance effect device according to claim 3 , wherein the first region has a portion having the Mn/Cr ratio of 1 or more.

5. The tunnel magnetoresistance effect device according to claim 1 , wherein the antiferromagnetic layer comprises a laminate of a PtCr layer and an X0Mn Layer (wherein X0 is one or two or more elements selected from the group consisting of the platinum group elements and Ni) nearer to the ferromagnetic layer than the PtCr layer.

6. The tunnel magnetoresistance effect device according to claim 1 , wherein the antiferromagnetic layer comprises a laminate of a PtCr layer and a PtMn layer in this order so that the PtMn layer is nearer to the ferromagnetic layer.

7. The tunnel magnetoresistance effect device according to claim 6 , wherein an IrMn layer is further laminated nearer to the ferromagnetic layer than the PtMn layer.

8. The tunnel magnetoresistance effect device according to claim 1 , wherein the tunnel magnetoresistance effect device is disposed on a substrate; and

the fixed magnetic layer is laminated nearer to the substrate than the free magnetic layer.

9. The tunnel magnetoresistance effect device according to claim 1 , wherein the tunnel magnetoresistance effect device is disposed on a substrate; and

the fixed magnetic layer is laminated farther away from the substrate than the free magnetic layer.

10. A tunnel magnetoresistance effect device comprising:

a structure comprising a fixed magnetic layer having a ferromagnetic layer and a free magnetic layer that is laminated through an insulating barrier layer, wherein:

the ferromagnetic layer and an antiferromagnetic layer laminated on the ferromagnetic layer constitute an exchange coupling film; and

the antiferromagnetic layer has an alternately laminated structure of three or more layers in which an X1Cr layer (wherein X1 is one or two or more elements selected from the group consisting of the platinum group elements and Ni) and an X2Mn layer (wherein X2 is one or two or more elements selected from the group consisting of the platinum group elements and Ni and may be the same as or different from X1) are alternately laminated.

11. The tunnel magnetoresistance effect device according to claim 10 , wherein X1 is Pt, and X2 is Pt or Ir.

12. The tunnel magnetoresistance effect device according to claim 10 , wherein the antiferromagnetic layer has a unit laminated portion in which a plurality of units each including the X1Cr layer and the X2Mn layer are laminated.

13. The tunnel magnetoresistance effect device according to claim 12 , wherein in the unit laminated portion, the X1Cr layers have the same thickness and the X2Mn layers have the same thickness, and the thickness of X1Cr layers is larger than the thickness of the X2Mn layers.

14. The tunnel magnetoresistance effect device according to claim 13 , wherein the ratio of the thickness of the X1Cr layer to the thickness of the X2Mn layer is 5:1 to 100:1.

15. The tunnel magnetoresistance effect device according to claim 10 , wherein the tunnel magnetoresistance effect device is disposed on a substrate; and

the fixed magnetic layer is laminated to be nearer to the substrate than the free magnetic layer.

16. The tunnel magnetoresistance effect device according to claim 10 , wherein the tunnel magnetoresistance effect device is disposed on a substrate; and

the fixed magnetic layer is laminated farther away from the substrate than the free magnetic layer.

17. A magnetic device comprising:

a tunnel magnetoresistance effect device; wherein

the tunnel magnetoresistance effect device comprises:

a structure comprising a fixed magnetic layer having a ferromagnetic layer and a free magnetic layer that is laminated through an insulating barrier layer, wherein:

the ferromagnetic layer and an antiferromagnetic layer laminated on the ferromagnetic layer constitute an exchange coupling film;

the antiferromagnetic layer has an alternately laminated structure of three or more layers in which an X1Cr layer (wherein X1 is one or two or more elements selected from the group consisting of the platinum group elements and Ni) and an X2Mn layer (wherein X2 is one or two or more elements selected from the group consisting of the platinum group elements and Ni and may be the same as or different from X1) are alternately laminated;

the X(Cr—Mn) layer has a first region relatively near the ferromagnetic layer, and a second region relatively far away from the ferromagnetic layer; and

the content of Mn in the first region is higher than that in the second region;

wherein:

the antiferromagnetic layer has a unit laminated portion in which a plurality of units each including the X1Cr layer and the X2Mn layer are laminated; and

in the unit laminated portion, the X1Cr layers have the same thickness and the X2Mn layers have the same thickness, and the thickness of X1Cr layers is larger than the thickness of the X2Mn layers.

18. The magnetic device according to claim 17 , comprising a magnetic head including the tunnel magnetoresistance effect device as a reading device.

19. The magnetic device according to claim 17 , comprising a magnetic memory including the tunnel magnetoresistance effect device as a recording device.

20. The magnetic device according to claim 17 , comprising a magnetic sensor having the tunnel magnetoresistance effect device as a detection device.

21. An apparatus comprising:

a magnetic device wherein the magnetic device comprises:

a tunnel magnetoresistance effect device comprising:

a structure comprising a fixed magnetic layer having a ferromagnetic layer and a free magnetic layer that is laminated through an insulating barrier layer, wherein:

the ferromagnetic layer and an antiferromagnetic layer laminated on the ferromagnetic layer constitute an exchange coupling film;

the antiferromagnetic layer includes an X(Cr—Mn) layer containing one or two or more elements X selected from the group consisting of the platinum group elements and Ni, and also containing Mn and Cr;

the X(Cr—Mn) layer has a first region relatively near the ferromagnetic layer, and a second region relatively far away from the ferromagnetic layer; and

the content of Mn in the first region is higher than that in the second region;

wherein:

the tunnel magnetoresistance effect device is disposed on a substrate; and

the fixed magnetic layer is laminated farther away from the substrate than the free magnetic layer.