Self-aligned double flux guided TMR sensor
View Patent ↗A magnetic head according to one embodiment includes an array of sensor structures formed on a common substrate. Each sensor structure further comprises: a magnetic tunnel junction sensor spaced from a media-facing surface of the head; and a flux guide between the media-facing surface of the head and the sensor, the flux guide guiding magnetic flux from a magnetic medium adjacent the media-facing surface to the sensor. Additional systems and methods are also presented.
1. A magnetic head, comprising:
an array of sensor structures formed on a common substrate, each sensor structure further comprising:
a magnetic tunnel junction sensor spaced from a media-facing surface of the head; and
a flux guide between the media-facing surface of the head and the sensor, the flux guide guiding magnetic flux from a magnetic medium adjacent the media-facing surface to the sensor.
2. The head of claim 1 , wherein the flux guide is self aligned with the sensor.
3. The head of claim 1 , further comprising a rear flux guide positioned behind the sensor relative to the media-facing surface.
4. The head of claim 3 , wherein the rear flux guide is self aligned with the sensor.
5. The head of claim 3 , further comprising insulated hard magnets oriented along sides of the sensor and flux guides for stabilizing magnetic moments of the sensor and flux guides.
6. The head of claim 3 , wherein a ratio of a track width of the sensor to a total stripe height of the flux guide, sensor and rear flux guide is greater than 1.
7. The head of claim 3 , wherein a ratio of a track width of the sensor to a total stripe height of the flux guide, sensor and rear flux guide is between about 1.5 and about 5.0.
8. The head of claim 1 , further comprising shield layers above and below the sensor, and gap layers between the sensor and the shield layers, wherein the gap layers are nonmagnetic and electrically conductive, wherein the gap layers each have a mechanical hardness greater than 80/20 NiFe.
9. The head of claim 8 , wherein the gap layers comprise a material selected from a group consisting of Rh, Cr and Ta.
10. The head of claim 1 , wherein the flux guide comprises a nitrogenated iron-containing alloy.
11. The head of claim 1 , wherein a thickness of the flux guide in a region thereof positioned closest to the media-facing surface is between about 5 and about 30 times as thick as a tunnel barrier layer of the sensor.
12. The head of claim 1 , further comprising an insulating layer between the flux guide and an underlying substrate, wherein a thickness of the insulating layer in a region thereof positioned closest to the media-facing surface is greater than a thickness of the insulating layer in a region thereof positioned closest to the sensor.
13. The head of claim 1 , wherein the flux guide has an absolute magnetostriction of about 10 −5 λ or less.
14. A magnetic tape head, comprising:
an array of sensor structures, each sensor structure further comprising:
a magnetic tunnel junction sensor spaced from a media-facing surface of the head;
a flux guide between the media-facing surface of the head and the sensor, the flux guide guiding magnetic flux from a magnetic medium adjacent the media-facing surface to the sensor;
a rear flux guide positioned behind the sensor relative to the media-facing surface;
shield layers above and below the sensor; and
nonmagnetic, electrically conductive gap layers between the sensor and the shield layers.
15. The head of claim 14 , wherein the flux guide is self aligned with the sensor, wherein the rear flux guide is self aligned with the sensor.
16. The head of claim 14 , further comprising insulated hard magnets oriented along sides of the sensor and flux guides for stabilizing magnetic moments of the sensor and flux guides.
17. The head of claim 14 , wherein a ratio of a track width of the sensor to a total stripe height of the flux guide, sensor and rear flux guide is greater than 1.
18. The head of claim 14 , wherein a ratio of a track width of the sensor to a total stripe height of the flux guide, sensor and rear flux guide is between about 1.5 and about 5.0.
19. The head of claim 14 , wherein the flux guide comprises a nitrogenated iron-containing alloy.
20. The head of claim 14 , wherein a thickness of the flux guide in a region thereof positioned closest to the media-facing surface is between about 5 and about 30 times as thick as a tunnel barrier layer of the sensor.
21. The head of claim 14 , wherein the flux guide has a magnetostriction of about 10 −5 λ or less.
22. The head of claim 14 , further comprising an insulating layer between the flux guide and an underlying substrate, wherein a thickness of the insulating layer in a region thereof positioned closest to the media-facing surface is greater than a thickness of the insulating layer in a region thereof positioned closest to the sensor.