Microwave assisted magnetic recording head having spin torque oscillator frequency detection

Patent metadata

Field	Value
Publication number	US-9858952-B1
Application number	US-201615199833-A
Country	US
Kind code	B1
Filing date	Jun 30, 2016
Priority date	Jun 30, 2016
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A magnetic write head having a spin torque oscillator with a magnetic field sensor for accurately determining magnetic field oscillation frequency. The spin torque oscillator has one or more tunnel junction (TMR) sensors formed at the side of the spin torque oscillator. The TMR sensor advantageously detects a magnetic field signal that is an additive signal of both fields from the spin polarization layer and the magnetic field generation layer, thereby providing efficient detection of magnetic field and associated oscillation frequency.

First claim

What is claimed is:

1. A magnetic write head, comprising:
a spin torque oscillator having a leading edge, a trailing edge and a side extending from the leading edge to the trailing edge; and
a magnetic sensor formed at the side of the spin torque oscillator.

2. The magnetic write head as in claim 1 , wherein the spin torque oscillator further comprises a magnetic spin polarization layer, a magnetic field generation layer, and a non-magnetic interlayer located between the magnetic spin polarization layer and the magnetic field generation layer.

3. The magnetic write head as in claim 1 , wherein the magnetic sensor includes a non-magnetic barrier layer, a magnetic layer and a non-magnetic electrically conductive lead.

4. The magnetic write head as in claim 1 , wherein the magnetic sensor further includes a non-magnetic barrier layer formed on the side of the spin torque oscillator, a magnetic layer formed on the non-magnetic barrier layer, and a non-magnetic, electrically conductive lead, wherein the non-magnetic barrier layer is located between the magnetic layer and the spin torque oscillator and the magnetic layer is located between the lead and the non-magnetic barrier layer.

5. The magnetic write head as in claim 3 , wherein the non-magnetic barrier layer comprises Mg—O, and the magnetic layer comprises Co—Fe—B.

6. The magnetic write head as in claim 3 , wherein the non-magnetic, electrically conductive lead is connected with circuitry for measuring a change in electrical resistance of the non-magnetic barrier layer.

7. The magnetic write head as in claim 3 , wherein the non-magnetic, electrically conductive lead is connected with circuitry for measuring a voltage across the non-magnetic barrier layer and the magnetic layer.

8. The magnetic write head as in claim 1 , wherein the spin torque oscillator and the magnetic sensor are both located between a magnetic write pole and a trailing magnetic shield.

9. The magnetic write head as in claim 1 , further comprising a second magnetic sensor located at a second side of the spin torque oscillator.

10. The magnetic write head as in claim 1 , wherein the side of the spin torque oscillator is a stripe height defining side located opposite a media facing surface.

11. A magnetic data recording system, comprising:
a housing;
a magnetic media held within the housing;
an actuator mounted within the housing;
a slider connected with the actuator for movement adjacent to a surface of the magnetic media; and
a magnetic recording head formed on the slider, the magnetic recording head including:
a spin torque oscillator having a leading edge, a trailing edge and a side extending from the leading edge to the trailing edge; and
a magnetic sensor formed at the side of the spin torque oscillator.

12. The magnetic data recording system as in claim 11 , wherein the spin torque oscillator further comprises a magnetic spin polarization layer, a magnetic field generation layer, and a non-magnetic interlayer located between the magnetic spin polarization layer and the magnetic field generation layer.

13. The magnetic data recording system as in claim 12 , wherein the magnetic sensor includes a non-magnetic barrier layer, a magnetic layer and a non-magnetic electrically conductive lead.

14. The magnetic data recording system as in claim 12 , wherein the magnetic sensor further includes a non-magnetic barrier layer formed on the side of the spin torque oscillator, a magnetic layer formed on the non-magnetic barrier layer, and a non-magnetic, electrically conductive lead, wherein the non-magnetic barrier layer is located between the magnetic layer and the spin torque oscillator and the magnetic layer is located between the lead and the non-magnetic barrier layer.

15. The magnetic data recording system as in claim 14 , wherein the non-magnetic barrier layer comprises Mg—O, and the magnetic layer comprises Co—Fe—B.

16. The magnetic data recording system as in claim 13 , wherein the non-magnetic, electrically conductive lead is connected with circuitry for measuring a change in electrical resistance of the non-magnetic barrier layer.

17. The magnetic data recording system as in claim 13 , wherein the non-magnetic, electrically conductive lead is connected with circuitry for measuring a voltage across the non-magnetic barrier layer and the magnetic layer.

18. The magnetic data recording system as in claim 12 , wherein the spin torque oscillator and the magnetic sensor are both located between a magnetic write pole and a trailing magnetic shield.

19. The magnetic data recording system as in claim 12 , further comprising a second magnetic sensor located at a second side of the spin torque oscillator.

20. The magnetic data recording system as in claim 12 , wherein the side of the spin torque oscillator is a stripe height defining side located opposite a media facing surface.

Assignees

• HGST Netherlands BV
• Western Digital Tech Inc

Inventors

• Sato Masashige
• Okamura Susumu
• Sato Yo
• Nagasaka Keiichi

Classifications

• 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

• G11B5/314 Primary

  where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers (G11B5/3196 takes precedence) · CPC title

• G11B5/3146

  magnetic layers · CPC title

• G11B2005/0024

  Microwave assisted recording · CPC title

• G11B5/3163

  Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers · CPC title