Magnetic bias pinning layer for GMR sensor of a magnetic head for a hard disk drive

1. A magnetic head comprising:

a free magnetic layer;

a bias layer having a width and being disposed parallel to the free magnetic layer and configured to induce a bias magnetic field in the free magnetic layer; and

a bias pinning layer disposed parallel to the bias layer, having a width that is greater than the bias layer width, and configured to induce a stabilization magnetic field in the bias layer.

2. A magnetic head according to claim 1 , wherein the width of the bias pinning layer is at least three times the width of the bias layer.

3. A magnetic head according to claim 1 , wherein the bias pinning layer includes cobalt samarium (CoSm) or cobalt platinum chromium (CoPtCr).

4. A magnetic head according to claim 1 , wherein the bias pinning layer includes cobalt samarium having between 60 at. % and 95 at. % cobalt and between 40 at. % and 5 at. % samarium.

5. A magnetic head according to claim 1 , wherein the bias pinning layer includes cobalt platinum chromium having between approximately 80 at. % and 68 at. % cobalt, approximately 12 at. % platinum, and between approximately 8 at. % and 20 at. % chromium.

6. A magnetic head according to claim 1 , wherein the bias pinning layer has a thickness that is between approximately 10 angstroms (Å) and approximately 50 Å.

7. A magnetic head according to claim 1 , wherein:

the bias pinning layer includes a bias pinning material and has a bias pinning thickness; and

the bias pinning material and the bias pinning thickness are selected such that the bias pinning layer has high coercivity and high resistivity.

8. A magnetic head according to claim 1 , further including a pinned magnetic layer structure having a width that is substantially greater than a width of the free magnetic layer.

9. A magnetic head according to claim 1 , further including:

an anti-ferromagnetic layer having a width that is substantially greater than a width of the free layer; and

a pinned magnetic layer structure having a width that is substantially greater than the width of the free magnetic layer.

10. A magnetic head according to claim 9 wherein the width of the pinned magnetic layer structure is at least three times the width of the free magnetic layer.

11. A magnetic head according to claim 1 , further including a pinned magnetic layer structure including a first pinned magnetic layer, an antiparallel coupling layer and a second pinned magnetic layer, wherein said second pinned magnetic layer has a width that is approximately equal to a width of the free magnetic layer and the first pinned magnetic layer has a width that is at least three times the width of the second pinned magnetic layer.

12. A hard disk drive for reading and writing information in a magnetic medium, the disk drive comprising:

a disk having a surface that includes the magnetic medium;

a motor coupled to rotate the disk;

a slider having an air bearing surface;

an actuator configured to hold the air bearing surface of the slider proximate to the surface of the disk;

a magnetic head disposed within the slider and forming part of the air bearing surface, wherein the magnetic head includes:

i) a free magnetic layer;

ii) a bias layer having a width and being disposed parallel to the free magnetic layer and configured to induce a bias magnetic field in the free magnetic layer; and

iii) a bias pinning layer disposed parallel to the free magnetic layer and the bias layer, having a width that is greater than the bias layer width, and configured to induce a stabilization magnetic field in the bias layer.

13. A hard disk drive according to claim 12 , wherein the width of the bias pinning layer is at least three times the width of the bias layer.

14. A hard disk drive according to claim 12 , wherein the bias pinning layer includes cobalt samarium (CoSm) or cobalt platinum chromium (CoPtCr).

15. A hard disk drive according to claim 12 , wherein the bias pinning layer includes cobalt samarium having between 60 at. % and 95 at. % cobalt and between 40 at. % and 5 at. % samarium.

16. A hard disk drive according to claim 12 , wherein the bias pinning layer includes cobalt platinum chromium having between approximately 80 at. % and 68 at. % cobalt, approximately 12 at. % platinum, and between approximately 8 at. % and 20 at. % chromium.

17. A hard disk drive according to claim 12 , wherein the bias pinning layer has a thickness that is between approximately 10 angstroms (Å) and approximately 50 Å.

18. A hard disk drive according to claim 12 , wherein:

the bias pinning layer includes a bias pinning material and has a bias pinning thickness; and

the bias pinning material and the bias pinning thickness are selected such that the bias pinning layer has high coercivity and high resistivity.

19. A hard disk drive according to claim 12 , further including a pinned magnetic layer structure having a width that is substantially greater than a width of the free magnetic layer.

20. A hard disk drive according to claim 12 , further including:

an anti-ferromagnetic layer having a width that is substantially greater than a width of the free layer; and

a pinned magnetic layer structure having a width that is substantially greater than the width of the free magnetic layer.

21. A hard disk drive according to claim 20 wherein the width of the pinned magnetic layer structure is at least three times the width of the free magnetic layer.

22. A hared disk drive according to claim 12 , furhter including a pinned magnetic layer structure including a first pinned magnetic layer, an antiparallel coupling layer and a second pinned magnetic layer, wherein said second pinned magnetic layer has a width that is approximately equal to a width of the free magnetic layer and the first pinned magnetic layer has a width that is at least three times the width of the second pinned magnetic layer.