Data reader with front shield coupling structure

1. An apparatus comprising a magnetoresistive stack positioned on an air bearing surface (ABS), a portion of the magnetoresistive stack set to a first fixed magnetization by a pinning structure separated from the ABS by a front shield, the front shield set to a second fixed magnetization by a biasing structure, the front shield separated from the biasing structure by a coupling structure.

2. The apparatus of claim 1 , wherein the magnetoresistive stack comprises a magnetically free structure having a first stripe height as measured perpendicular to the ABS and a magnetically fixed structure set to the first fixed magnetization and having a second stripe height from the ABS, the first stripe height being smaller than the second stripe height.

3. The apparatus of claim 1 , wherein the pinning structure is separated from the front shield by a non-ferromagnetic transition metal layer.

4. The apparatus of claim 1 , wherein the pinning structure has a front surface proximal the ABS, the front surface canted at a non-normal angle with respect to the ABS.

5. The apparatus of claim 1 , wherein the coupling structure comprises CoFe.

6. The apparatus of claim 1 , wherein the coupling structure comprises NiFe.

7. The apparatus of claim 1 , wherein the coupling structure continuously extends from the ABS to separate the front shield from the biasing structure and the pinning structure.

8. The apparatus of claim 1 , wherein the second fixed magnetization is orthogonal to the first fixed magnetization.

9. The apparatus of claim 1 , wherein the coupling structure antiferromagnetically couples the front shield to the biasing structure.

10. The apparatus of claim 1 , wherein the coupling structure ferromagnetically couples the front shield to the biasing structure.

11. An apparatus comprising:

a magnetoresistive stack positioned on an air bearing surface (ABS);

a first pinning structure contacting the magnetoresistive stack to set a portion of the magnetoresistive stack to a first fixed magnetization; and

a front shield separating the first pinning structure from the ABS, the front shield set to a second fixed magnetization by a biasing structure, the front shield separated from the biasing structure by a first coupling structure comprising first and second coupling sub-layers.

12. The apparatus of claim 11 , wherein a second pinning structure of the biasing structure sets the second fixed magnetization.

13. The apparatus of claim 12 , wherein the second pinning structure comprises a synthetic antiferromagnet (SAF).

14. The apparatus of claim 13 , wherein a second coupling structure is disposed between first and second ferromagnetic layers of the SAF, the second coupling structure comprising a non-magnetic material disposed between first and second magnetic materials.

15. The apparatus of claim 12 , wherein the second pinning structure is disposed between the coupling structure and a shield layer.

16. The apparatus of claim 11 , wherein the first coupling sub-layer is non-magnetic and the second coupling sub-layer is magnetic.

17. The apparatus of claim 11 , wherein the first coupling sub-layer is a transition metal material and is disposed between the second coupling sub-layer and a third coupling sub-layer, the second and third coupling sub-layers each being a common magnetic material.

18. The apparatus of claim 17 , wherein the common magnetic material comprises CoFe.