MICROWAVE-ASSISTED MAGNETIC RECORDING HEAD AND MAGNETIC READ/WRITE APPARATUS USING THE SAME

• US 20110216435A1
• Filed: 02/01/2011
• Published: 09/08/2011
• Est. Priority Date: 03/04/2010
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Igarashi, Masakazu, SHIIMOTO, MASATO, Furukawa, Masaru
• Granted Patent: US 8,582,225 B2
• Time in Patent Office: Days
• US Class Current: 360/59
• CPC Class Codes: G11B 2005/0024 Microwave assisted recording
• CPC Class Codes: G11B 5/02 Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/3116 Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks G11B5/3113, G11B5/245 take precedence
• CPC Class Codes: G11B 5/3133 including layers not usually being a part of the electromagnetic transducer structure and providing additional features, e.g. for improving heat radiation, reduction of power dissipation, adaptations for measurement or indication of gap depth or other properties of the structure G11B5/3106 takes precedence
• CPC Class Codes: G11B 5/314 where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers G11B5/3196 takes precedence
• CPC Class Codes: G11B 5/3146 magnetic layers

Abstract

A microwave-assisted magnetic recording head includes: a main magnetic pole that generates a recording magnetic field to be recorded on a magnetic recording medium; a shield; and an oscillator that is provided between the main magnetic pole and the shield and generates a microwave magnetic field. The microwave-assisted magnetic recording head is provided with a thermal expansion device for adjusting a relative position between the oscillator and the main magnetic pole so as to be able to independently adjust a recording magnetic field from the main magnetic pole and a microwave magnetic field from the oscillator.

Claims

1. A microwave-assisted magnetic recording head comprising:

a main magnetic pole that generates a recording magnetic field to be recorded on a magnetic recording medium;

a shield; and

an oscillator that is provided between the main magnetic pole and the shield and generates a microwave magnetic field,

wherein the microwave-assisted magnetic recording head is provided with a feature for adjusting a relative position between the oscillator and the main magnetic pole.

2. The microwave-assisted magnetic recording head according to claim 1,

wherein the feature for adjusting a relative position adjusts a relative distance between a bottom face of the oscillator and a bottom face of the main magnetic pole toward a recording medium.

3. The microwave-assisted magnetic recording head according to claim 2,

wherein the feature for adjusting a relative distance toward a recording medium includes:

a first thermal expansion device that is provided opposite a face of the oscillator toward a recording medium;

an insulation layer that is made of an insulating material and is provided between the oscillator and the first thermal expansion device; and

an electrode for applying an electric current to the first thermal expansion device.

4. The microwave-assisted magnetic recording head according to claim 3,

wherein a bottom face of the oscillator is higher than a bottom face of the main magnetic pole with reference to a recording medium while no electric current is applied to the first thermal expansion device.

5. The microwave-assisted magnetic recording head according to claim 3,

wherein a bottom face of the oscillator levels with a bottom face of the main magnetic pole while no electric current is applied to the first thermal expansion device.

6. The microwave-assisted magnetic recording head according to claim 1,

wherein the feature for adjusting a relative position adjusts a relative distance between the oscillator and the main magnetic pole in a head travel direction.

7. The microwave-assisted magnetic recording head according to claim 6,

wherein the feature for adjusting a relative distance in a head travel direction includes:

a second thermal expansion device provided for the shield opposite the oscillator;

an insulation layer that is made of an insulating material and is provided between and adjacent to the shield and the second thermal expansion device; and

an electrode for applying an electric current to the second thermal expansion device.

8. The microwave-assisted magnetic recording head according to claim 6,

wherein a gap is provided between the main magnetic pole and the oscillator.

9. The microwave-assisted magnetic recording head according to claim 1,

wherein the feature for adjusting a relative position includes both of:

a feature for adjusting a relative distance between the oscillator and the main magnetic pole in a head travel direction; and

a feature for adjusting a relative distance between a bottom face of the oscillator and a bottom face of the main magnetic pole toward a recording medium.

10. The microwave-assisted magnetic recording head according to claim 9,

wherein the feature for adjusting a relative distance toward a recording medium includes:

a first thermal expansion device that is provided opposite a face of the oscillator toward a recording medium;

an insulation layer that is made of an insulating material and is provided between the oscillator and the first thermal expansion device; and

an electrode for applying an electric current to the first thermal expansion device.

wherein the feature for adjusting a relative distance in a head travel direction includes;

a second thermal expansion device provided for the shield opposite the oscillator;

an insulation layer that is made of an insulating material and is provided between and adjacent to the shield and the second thermal expansion device; and

an electrode for applying an electric current to the second thermal expansion device.

11. The microwave-assisted magnetic recording head according to claim 1, comprising:

a feature that simultaneously adjusts positions of the main magnetic pole and oscillator toward a recording medium.

12. The microwave-assisted magnetic recording head according to claim 11,

wherein the feature for adjusting positions toward a recording medium is equivalent to a third thermal expansion device.

13. The microwave-assisted magnetic recording head according to claim 1,

wherein the oscillator includes a microwave magnetic field generation layer.

14. The microwave-assisted magnetic recording head according to claim 13,

wherein the oscillator includes a spin injection fixing layer, an intermediate layer, a microwave magnetic field generation layer, and a rotation guide layer.

15. A magnetic read/write apparatus comprising:

a microwave-assisted magnetic recording head including;

a main magnetic pole that generates a recording field to be recorded on a magnetic recording medium;

a shield;

an oscillator that is provided between the main magnetic pole and the shield and generates a microwave magnetic field; and

a feature for adjusting a relative position between the oscillator and the main magnetic pole;

a magnetic read head that reads information from a magnetic recording medium; and

a signal processing means that processes a signal written by the magnetic recording head and a signal read by the magnetic read head.

16. The magnetic read/write apparatus according to claim 15,

wherein the feature of the microwave-assisted magnetic recording head for adjusting a relative position adjusts a relative distance between a bottom face of the oscillator and a bottom face of the main magnetic pole toward a recording medium.

17. The magnetic read/write apparatus according to claim 15,

wherein the feature of the microwave-assisted magnetic recording head for adjusting a relative position adjusts a relative distance between the oscillator and the main magnetic pole in a head travel direction.

18. The magnetic read/write apparatus according to claim 15,

wherein the feature of the microwave-assisted magnetic recording head for adjusting a relative position includes both of:

a feature for adjusting a relative distance between the oscillator and the main magnetic pole in a head travel direction; and

a feature for adjusting a relative distance between a bottom face of the oscillator and a bottom face of the main magnetic pole toward a recording medium.