Granted Patent B1

US 8,547,730 · App. 12/712,085 · Granted Oct 1, 2013

Abstract

Claims (22)

1. A spin tunneling element comprising:

a pinned layer;

a barrier layer having a first crystal structure, and having a texture; and

a free layer having a first ferromagnetic layer and a second ferromagnetic layer, the first ferromagnetic layer adjoining and sharing an interface with the second ferromagnetic layer and between the second ferromagnetic layer and the barrier layer, the first ferromagnetic layer having the first crystal structure and the texture, the second ferromagnetic layer having a second crystal structure different from the first crystal structure, the free layer having a coercivity of not more than five Oersted.

2. The spin tunneling element of claim 1 wherein the barrier layer includes MgO.

3. The spin tunneling element of claim 2 wherein the barrier layer includes MgOX, where X is a nonmagnetic material.

4. The spin tunneling element of claim 2 wherein the texture is [100].

5. The spin tunneling element of claim 4 wherein the second ferromagnetic layer includes NiFe.

6. The spin tunneling element of claim 2 wherein the first ferromagnetic layer includes CoFe.

7. The spin tunneling element of claim 6 wherein the first ferromagnetic layer includes CoFeX, where X includes at least one of B and another nonmagnetic material.

8. The spin tunneling element of claim 1 wherein the first crystal structure is BCC.

9. The spin tunneling element of claim 8 wherein the second crystal structure is FCC.

10. The spin tunneling element of claim 1 wherein the free layer has an interlayer exchange coupling of not more than fifty Oersted.

11. The spin tunneling element of claim 1 wherein the free layer has a magnetostriction having an absolute value of not more than 1.0×10 −6 .

12. A spin tunneling element comprising:

a pinned layer;

a barrier layer, the barrier layer including crystalline MgO and having a [100] texture; and

a free layer having a layer including CoFe and a NiFe layer, the layer including CoFe adjoining and sharing an interface with the NiFe layer and being between the NiFe layer and the barrier layer, the layer including CoFe having a body centered cubic (BCC) crystal structure and the [100] texture, the NiFe layer having a FCC crystal structure, the free layer having a coercivity of not more than five Oersted, an interlayer exchange coupling of not more than fifty Oersted, and a magnetostriction having an absolute value of not more than 1.0×10 −6 .

13. A transducer comprising:

a read head including a spin tunneling element having a pinned layer, a barrier layer, and a free layer, the barrier layer having a first crystal structure and a texture, the free layer having a first ferromagnetic layer and a second ferromagnetic layer, the first ferromagnetic being adjoining and sharing an interface with the second ferromagnetic layer and between the second ferromagnetic layer and the barrier layer, the first ferromagnetic layer having the first crystal structure and the texture, the second ferromagnetic layer having a second crystal structure different from the first crystal structure, the free layer having a coercivity of not more than five Oersted.

14. The transducer of claim 13 wherein the free layer has an interlayer exchange coupling of not more than fifty Oersted.

15. The transducer of claim 13 wherein the free layer has a magnetostriction having an absolute value of not more than 1.0×10 −6 .

Assignments (9)