High frequency field assisted write device

• US 7,724,469 B2
• Filed: 12/06/2006
• Issued: 05/25/2010
• Est. Priority Date: 12/06/2006
• Status: Expired due to Fees

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Xue, Song S., Gao, Kaizhong, Xi, Haiwen, Li, Shaoping, Mao, Sining, Ryan, Patrick J., Shi, Yiming
• Primary Examiner(s): KLIMOWICZ, WILLIAM JOSEPH
• Application Number:
  US11/634,767
• Publication Number:
  US 20080137224A1
• Time in Patent Office: 1,266 Days
• Field of Search: 360/128, 360/125.3, 360/125.31, 360/125.71, 360/125.74
• US Class Current: 360/125.3
• CPC Class Codes: G11B 2005/001 Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier

Abstract

A magnetic writer includes a write element and an oscillation device disposed adjacent to the write element. The first oscillation device includes a first magnetic layer, a second magnetic layer having a magnetization vector including a component perpendicular to a major plane of the first magnetic layer. The first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer. The first oscillation device generates a high-frequency oscillation field when a current is directed perpendicular to the major plane of the first magnetic layer.

Claims

1. A magnetic writer comprising:

a write element; and

a first oscillation device disposed adjacent to the write element, wherein the first oscillation device includes a first magnetic layer, a second magnetic layer having a magnetization vector including a component perpendicular to a major plane of the first magnetic layer, a first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer, and a third magnetic layer disposed adjacent to the second magnetic layer on a side opposite the first nonmagnetic layer, the third magnetic layer having a magnetization direction that is substantially parallel to a magnetization direction of the first magnetic layer, wherein the first oscillation device generates a high-frequency oscillation field when a current is directed perpendicular to the major plane of the first magnetic layer.

2. The magnetic writer of claim 1, wherein the frequency of the high-frequency oscillation field is related to an amplitude of the current.

3. The magnetic writer of claim 2, wherein the high-frequency oscillation field has a frequency of at least 1.0 GHz.

4. A magnetic writer comprising:

a write element;

a first oscillation device disposed adjacent to the write element, wherein the first oscillation device includes a first magnetic layer, a second magnetic layer having a magnetization vector including a component perpendicular to a major plane of the first magnetic layer, and a first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer, wherein the first oscillation device generates a high-frequency oscillation field when a current is directed perpendicular to the major plane of the first magnetic layer; and

a second oscillation device disposed adjacent to the first oscillation device and including a third magnetic layer, a fourth magnetic layer having a magnetization vector including a component perpendicular to a major plane of the third magnetic layer, and a second nonmagnetic layer disposed between the third magnetic layer and the fourth magnetic layer, wherein the current is directed perpendicular to the major plane of the third magnetic layer.

5. The magnetic writer of claim 4, wherein the second oscillation device is disposed in series with the first oscillation device.

6. The magnetic writer of claim 4, wherein the second oscillation device is disposed in parallel with the first oscillation device.

7. The magnetic writer of claim 4, wherein the high-frequency oscillation fields generated by the first and second oscillation devices are phase locked.

8. A magnetic writer comprising:

a write element that produces a write field through a front surface; and

a first oscillation device disposed adjacent to the write element at the front surface, wherein the first oscillation device includes a first magnetic layer, a second magnetic layer having a magnetization direction substantially perpendicular to a major plane of the first magnetic layer, a first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer, and a third magnetic layer disposed adjacent to the second magnetic layer on a side opposite the first nonmagnetic layer, the third magnetic layer having a magnetization direction that is substantially parallel to a magnetization direction of the first magnetic layer;

wherein the first oscillation device generates a high-frequency oscillation field that assists the write field when a current is directed perpendicular to the major plane of the first magnetic layer.

9. The magnetic writer of claim 8, wherein the current is selected from the group consisting of direct current, alternating current, and direct current with alternating current modulation.

10. The magnetic writer of claim 8, wherein at least one of the first and second magnetic layers is comprised of a material selected from the group consisting of Co, CoFe, CoFeB, NiFe, and alloys thereof.

11. The magnetic writer of claim 8, wherein the first nonmagnetic layer is comprised of a material selected from the group consisting of Cu, Ag, Au, Pt, Ag, Cr, Ru, and Pd.

12. A magnetic writer comprising:

a write element that produces a write field through a front surface;

a first oscillation device disposed adjacent to the write element at the front surface, wherein the first oscillation device includes a first magnetic layer, a second magnetic layer having a magnetization direction substantially perpendicular to a major plane of the first magnetic layer, and a first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer; and

wherein the first oscillation device generates a high-frequency oscillation field that assists the write field when a current is directed perpendicular to the major plane of the first magnetic layer; and

a second oscillation device disposed adjacent to the first oscillation device and including a third magnetic layer, a fourth magnetic layer having a magnetization direction substantially perpendicular to a major plane of the third magnetic layer, and a second nonmagnetic layer disposed between the third magnetic layer and the fourth magnetic layer, wherein the current is directed perpendicular to the major plane of the third magnetic layer.

13. The magnetic writer of claim 12, wherein the second oscillation device is disposed in series with the first oscillation device.

14. The magnetic writer of claim 12, wherein the second oscillation device is disposed in parallel with the first oscillation device.

15. The magnetic writer of claim 12, wherein the high-frequency oscillation fields generated by the first and second oscillation devices are phase locked.

16. A magnetic writing system comprising:

a magnetic medium;

a write element disposed adjacent to the magnetic medium that produces a write field through a medium confronting surface; and

a first oscillation device disposed adjacent to the write element at the medium confronting surface, wherein the first oscillation device includes a first magnetic layer, a second magnetic layer having a magnetization direction substantially perpendicular to a major plane of the first magnetic layer, a first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer, and a third magnetic layer disposed adjacent to the second magnetic layer on a side opposite the first nonmagnetic layer, the third magnetic layer having a magnetization direction that is substantially perpendicular to the magnetization direction of the second magnetic layer;

wherein the first oscillation device generates a high-frequency oscillation field that reduces the coercivity of the magnetic medium proximate to the write element when a current is directed perpendicular to the major plane of the first magnetic layer.

17. The magnetic writing system of claim 16, wherein the frequency of the high-frequency oscillation field is related to an amplitude of the current.

18. The magnetic writing system of claim 16, and further comprising:

a fourth magnetic layer having a magnetization direction substantially perpendicular to a major plane of the third magnetic layer; and

a second nonmagnetic layer disposed between the third magnetic layer and the fourth magnetic layer.

19. The magnetic writing system of claim 16, wherein the current is selected from the group consisting of direct current, alternating current, and direct current with alternating current modulation.

20. A magnetic writing system comprising:

a magnetic medium;

a write element disposed adjacent to the magnetic medium that produces a write field through a medium confronting surface;

a first oscillation device disposed adjacent to the write element at the medium confronting surface, wherein the first oscillation device includes a first magnetic layer, a second magnetic layer having a magnetization direction substantially perpendicular to a major plane of the first magnetic layer, and a first nonmagnetic layer disposed between the first magnetic layer and the second magnetic layer; and

wherein the first oscillation device generates a high-frequency oscillation field that reduces the coercivity of the magnetic medium proximate to the write element when a current is directed perpendicular to the major plane of the first magnetic layer;

a third magnetic layer;

a fourth magnetic layer having a magnetization direction substantially perpendicular to a major plane of the third magnetic layer; and

a second nonmagnetic layer disposed between the third magnetic layer and the fourth magnetic layer;

wherein the third magnetic layer is disposed relative to the first magnetic layer such that the current is directed in parallel perpendicular to the major planes of the first and third magnetic layers.