Recording heads using magnetic fields generated locally from high current densities in a thin film wire

• US 6,665,136 B2
• Filed: 02/27/2002
• Issued: 12/16/2003
• Est. Priority Date: 08/28/2001
• Status: Expired due to Term

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Clinton, Thomas William, Seigler, Michael Allen, Rottmayer, Robert Earl
• Primary Examiner(s): Hudspeth, David
• Assistant Examiner(s): DAVIDSON, DAN
• Application Number:
  US10/084,033
• Publication Number:
  US 20030043490A1
• Time in Patent Office: 657 Days
• Field of Search: 360/55, 360/126, 369/13.17
• US Class Current: 360/55
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: G11B 13/045 combined recording by magnetic and optic means
• CPC Class Codes: G11B 2005/0002 Special dispositions or recording techniques
• CPC Class Codes: G11B 2005/0005 Arrangements, methods or circuits
• CPC Class Codes: G11B 2005/0021 Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal
• CPC Class Codes: G11B 5/127 Structure or manufacture of heads, e.g. inductive
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/17 Construction or disposition of windings
• CPC Class Codes: G11B 5/313 Disposition of layers
• CPC Class Codes: G11B 5/743 Patterned record carriers, wherein the magnetic recording layer is patterned into magnetic isolated data islands, e.g. discrete tracks
• CPC Class Codes: Y10T 428/1186 with head pole component

Abstract

A method of recording information bits in a magnetic storage medium, the method comprising positioning a first conductor adjacent to a magnetic recording medium, the conductor having a width and a length, wherein a distance between the first conductor and the magnetic recording medium is less than or equal to the width and the length, and passing a first current through the conductor of sufficient magnitude to produce a magnetic field in the magnetic medium greater than one Tesla and having a magnetic field gradient in a cross track direction and a down track direction greater than 100 Oe/nm over a bit dimension. The thickness of the first conductor can be less than or equal to the distance between the first conductor and the magnetic recording medium. The current density in the conductor can be greater than 10⁹ ampere/cm², and the length of the conductor can be less than 100 nm. The current can be applied as one or more pulses in a predetermined clock cycle time. The magnetic field can be augmented by using an additional conductor, an adjacent ferromagnetic film, and/or a magnetic yoke and coil. Magnetic recording heads and disc drives that record data in accordance with the method are also included.

Claims

1. A method of recording information bits in a magnetic storage medium, the method comprising:

positioning a first conductor adjacent to a magnetic recording medium, the conductor having a width and a length, wherein a distance between the first conductor and the magnetic recording medium is less than or equal to the width and the length; and

passing a first current through the conductor of sufficient magnitude to produce a magnetic field in the magnetic medium greater than one Tesla and having a magnetic field gradient in a cross track direction and a down track direction greater than 100 Oe/nm over a bit dimension.

2. The method of claim 1, wherein the width and the length are approximately equal to a bit length and a track width in the magnetic recording medium.

3. The method of claim 1, wherein the first current is less than 100 mA.

4. The method of claim 1, wherein the density of the current in the first conductor is greater than 10⁹ ampere/cm².

5. The method of claim 1, wherein the length, width and thickness of the first conductor are each less than 100 nm.

6. The method of claim 1, further comprising:

positioning a layer of ferromagnetic material adjacent to the first conductor; and

using the layer of ferromagnetic material to augment the magnetic field.

7. The method of claim 1, further comprising:

positioning the first conductor between a write pole and a return pole of a magnetic yoke;

passing a second current through a coil to produce magnetic flux in the yoke; and

using the magnetic flux in the yoke to augment the magnetic field.

8. The method of claim 1, further comprising:

positioning an antenna adjacent to, or integral with, the first conductor; and

using the antenna to heat the magnetic medium.

9. The method of claim 1, further comprising:

positioning a second conductor adjacent to the magnetic recording medium and parallel to the first conductor, the second conductor having a width and a thickness, wherein the width is greater than the thickness; and

passing a second current through the second conductor to augment the magnetic field.

10. The method of claim 1, wherein the first current comprises a current pulse having a duration of less than a predetermined clock cycle time.

11. The method of claim 1, wherein the first current comprises a plurality of current pulses within a time period of the duration of a predetermined clock cycle time.

12. The method of claim 1, wherein the first conductor has a thickness that is less than or equal to the distance between the first conductor and the magnetic recording medium.

13. The method of claim 1, wherein the step of passing a first current through the conductor comprises:

passing the first current through a first contact connected to a first end of the first conductor; and

passing the first current through a second contact connected to a second end of the first conductor;

wherein the average current density in the first conductor is greater than 1000 times the average current density in each of the first and second contacts.

14. A recording head for use with a magnetic storage medium, comprising:

a first conductor having a width and a length;

means for positioning the first conductor adjacent to a magnetic recording medium, wherein a distance between the first conductor and the magnetic recording medium is less than or equal to the width and the length; and

means for passing a first current through the first conductor of sufficient magnitude to produce a magnetic field in the magnetic medium greater than one Tesla and a magnetic field gradient in a cross track direction and a down track direction greater than 100 Oe/nm over a bit dimension.

15. The recording head of claim 14, further comprising:

a layer of ferromagnetic material adjacent to the first conductor.

16. The recording head of claim 14, further comprising:

a magnetic yoke having a write pole and a return pole, wherein the first conductor is positioned between the write pole and the return pole; and

a coil for producing magnetic flux in the yoke.

17. The recording head of claim 14, further comprising:

an antenna adjacent to the first conductor.

18. The recording head of claim 14, wherein the means for positioning the first conductor adjacent to a magnetic recording medium, further positions the first conductor such that the distance between the first conductor and the magnetic recording medium is greater than or equal to the thickness of the first conductor.

19. The recording head of claim 14, wherein means for passing a first current through the first conductor comprises:

a first contact connected to a first end of the first conductor; and

a second contact connected to a second end of the first conductor;

wherein the cross-sectional area of each of the first and second contacts is greater than 1000 times the cross-sectional area of the first conductor.

20. A magnetic disc drive storage system, comprising:

a housing;

means for supporting a magnetic storage medium positioned in the housing; and

means for positioning a recording head adjacent to said rotatable magnetic storage medium, the recording head including a first conductor having a width and a length, wherein a distance between the first conductor and the magnetic recording medium is less than or equal to the width and the length, and means for passing a first current through the first conductor of sufficient magnitude to produce a magnetic field in the magnetic medium greater than one Tesla and a magnetic field gradient in a cross track direction and a down track direction greater than 100 Oe/nm over a bit dimension.

21. The magnetic disc drive storage system of claim 20, wherein the recording head further comprises:

a layer of ferromagnetic material adjacent to the first conductor.

22. The magnetic disc drive storage system of claim 20, wherein the recording head further comprises:

a magnetic yoke having a write pole and a return pole, wherein the first conductor is positioned between the write pole and the return pole; and

a coil for producing magnetic flux in the yoke.

23. The magnetic disc drive storage system of claim 20, wherein the recording head further comprises:

an antenna adjacent to the first conductor.

24. The magnetic disc drive storage system of claim 20, wherein the recording head further comprises:

a second conductor positioned parallel to the first conductor.

25. The magnetic disc drive storage system of claim 20, wherein the means for positioning the recording head adjacent to said rotatable magnetic storage medium, further positions the first conductor such that the distance between the first conductor and the magnetic storage medium is greater than or equal to the thickness of the first conductor.

26. The magnetic disc drive storage system of claim 20, wherein means for passing a first current through the first conductor comprises:

a first contact connected to a first end of the first conductor; and

a second contact connected to a second end of the first conductor;

wherein the cross-sectional area of each of the first and second contacts is greater than 1000 times the cross-sectional area of the first conductor.