Magnetoresistive sensor with variable shield permeability

Patent metadata

Field	Value
Publication number	US-9019664-B2
Application number	US-201313898210-A
Country	US
Kind code	B2
Filing date	May 20, 2013
Priority date	May 20, 2013
Publication date	Apr 28, 2015
Grant date	Apr 28, 2015

Abstract

Implementations disclosed herein allow a signal detected by a magnetoresistive (MR) sensor to be improved by providing for one or more regions of reduced anisotropy proximal to a sensor stack within a shielding structure.

First claim

What is claimed is:

1. A sensor apparatus comprising:
a sensor stack located within a shielding structure; and
permanent magnetic elements on opposite sides of the sensor stack, wherein a predetermined angular separation between a magnetic orientation of the permanent magnetic elements and a magnetic orientation of the shielding structure influences permeability of the shielding structure so that a first region of the shielding structure near the sensor stack has a permeability that is greater than a permeability of a second region of the shielding structure away from the sensor stack.

2. The sensor apparatus of claim 1 , wherein the first region is proximal to at least one of a leading or trailing edge of the sensor stack.

3. The sensor apparatus of claim 1 , wherein the magnetic orientation of the permanent magnetic elements is substantially antiparallel to the magnetic orientation of the shielding structure.

4. The sensor apparatus of claim 1 , wherein a magnetic orientation of the shielding structure is biased with domain control stabilization tabs.

5. The sensor apparatus of claim 1 , wherein the shielding structure includes a main shield element and a decoupled thin shield element.

6. The sensor apparatus of claim 1 , wherein the magnetic orientation of the material in the enhanced permeability region is substantially antiparallel to the magnetic orientation of the shielding structure.

7. An apparatus comprising:
a shield;
a sensor stack proximal to an inner surface of the shield, and
a local permeability tuning element, wherein a predetermined angular separation between a magnetic orientation of material of the local permeability tuning element and a magnetic orientation of the shield creates an enhanced permeability region within the shield, the enhanced permeability region having a permeability that is greater than a global permeability of the shield.

8. The apparatus of claim 7 , wherein the magnetic orientation of the material in the enhanced permeability region is substantially antiparallel to the magnetic orientation of the shield.

9. The apparatus of claim 7 , wherein the local permeability tuning element is recessed from an air bearing surface relative to the sensor stack.

10. The apparatus of claim 7 , wherein a magnetic orientation of the shielding structure is biased with domain control stabilization tabs.

11. The apparatus of claim 7 , wherein the shield includes a main shield element and a decoupled thin shield element.

12. The apparatus of claim 7 , further comprising side shields.

13. The apparatus of claim 7 , wherein the enhanced permeability region is proximal to at least one of a leading or trailing edge of the sensor stack.

14. A read element comprising:
a shield that includes a main shield element and a decoupled thin shield element, wherein the decoupled thin shield element is between the main shield element and a sensor stack; and
an enhanced permeability region within the decoupled thin shield element with a permeability that is greater than a global permeability of the shield.

15. The read element of claim 14 , further comprising:
permanent magnetic elements on opposite sides of a sensor stack, wherein a predetermined angular separation between a magnetic orientation of the permanent magnetic elements and a magnetic orientation of the decoupled thin shield element creates the enhanced permeability region.

16. The read element of claim 15 , wherein the magnetic orientation of the decoupled thin shield element is substantially antiparallel to the magnetic orientation of the permanent magnets.

17. The read element of claim 14 , further comprising a local permeability tuning element, wherein a predetermined angular separation between a magnetic orientation of the local permeability tuning element and a magnetic orientation of the decoupled thin shield element creates the enhanced permeability region.

18. The read element of claim 17 , wherein the material of the local permeability tuning element is at least one of a permanent magnetic material or an anti-ferromagnetic material.

19. The read element of claim 14 , wherein a magnetic orientation of the shielding structure is biased with domain control stabilization tabs.

Assignees

• Seagate Technology Llc

Inventors

• Song Dion
• Dimitrov Dimitar Velikov
• Sapozhnikov Victor Boris
• Patwari Mohammed Sharia Ullah

Classifications

• G11B5/11

  Shielding of head against electric or magnetic fields · CPC title

• G11B5/3912 Primary

  Arrangements in which the active read-out elements are transducing in association with active magnetic shields, e.g. magnetically coupled shields (G11B5/3916 takes precedence) · CPC title