THREE-DIMENSIONAL MAGNETIC RECORDING AND REPRODUCING APPARATUS

• US 20120224283A1
• Filed: 03/09/2012
• Published: 09/06/2012
• Est. Priority Date: 09/11/2009
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: SATO, Rie, Mizushima, Koichi, Nagasawa, Tazumi, Kudo, Kiwamu
• Granted Patent: US 9,001,466 B2
• Time in Patent Office: Days
• US Class Current: 360/324.11
• 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 5/3133 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 5/678 having three or more magnetic layers
• CPC Class Codes: G11B 5/82 Disk carriers

Abstract

According to one embodiment, a three-dimensional magnetic recording and reproducing apparatus includes a magnetic head and a magnetic storage medium. The magnetic head includes a spin-torque oscillator including a free layer, a non-magnetic layer and a fixed layer, magnetization of the free layer being rotatable, the non-magnetic layer being laminated on the free layer, the fixed layer being laminated on the non-magnetic layer, a magnetization direction of the fixed layer being fixed. The magnetic storage medium includes first magnetic layers formed of magnetic materials having different resonant frequencies, each of the first magnetic layers being formed of an in-plane magnetization film and having recording tracks.

Claims

1. A three-dimensional magnetic recording and reproducing apparatus, comprising:

a magnetic head comprising a spin-torque oscillator, the spin-torque oscillator comprising a free layer, a first non-magnetic layer and a fixed layer, magnetization of the free layer being rotatable, the first non-magnetic layer being laminated on the free layer, the fixed layer being laminated on the first non-magnetic layer, a magnetization direction of the fixed layer being fixed; and

a magnetic storage medium comprising a plurality of first magnetic layers formed of magnetic materials having different resonant frequencies, each of the first magnetic layers being formed of an in-plane magnetization film and having recording tracks.

2. The apparatus according to claim 1, wherein each recording track comprises a plurality of first regions, each first region has a magnetization direction, and at least one of the first regions has such magnetization direction that is parallel to a track surface of the recording tracks and is perpendicular to a track direction.

3. The apparatus according to claim 2, wherein the magnetic storage medium further comprises a non-magnetic material and second regions in addition to the first regions, the non-magnetic material being between the first regions, the second regions being formed of a soft magnetic material and connected to each of the first regions via the non-magnetic material.

4. The apparatus according to claim 1, wherein the first magnetic layers of the magnetic storage medium are in an ascending order of a resonant frequency, from a first magnetic layer closest to the magnetic head to a first magnetic layer farthest from the magnetic head.

5. The apparatus according to claim 4, wherein if a data item is read from the recording tracks by the magnetic head, a frequency of oscillation of the spin-torque oscillator is the same as a resonant frequency of a layer of the first magnetic layers in which the data item is written, if the data item is written to the recording tracks by the magnetic head, the frequency of oscillation is the same as a resonant frequency of a layer of the first magnetic layers in which the data item to be written.

6. The apparatus according to claim 5, wherein if the data item is read from or written to the recording tracks by the magnetic head, the magnetic head further comprises a magnetic pole to adjust a resonant frequency of the first region, a distance between the magnetic pole and the spin-torque oscillator is set in a manner such that, if the data item is read, the high-frequency magnetic field created by the spin-torque oscillator reaches to the first region, and if the data item is written, the high-frequency magnetic field reaches to the first region.

7. The apparatus according to claim 6, wherein if the data item is read from the recording track by the magnetic head, at least either one of a power change of the electromagnetic wave or a phase change of the electromagnetic wave emitted from the magnetic oscillator is detected.

8. The apparatus according to claim 6, wherein the magnetic pole is ring-type magnetic pole.

9. The apparatus according to claim 1, wherein the free layer is formed of with an in-plane magnetization film, and the fixed layer is formed of a perpendicular magnetization film.

10. The apparatus according to claim 9, wherein if the data item is read from or written to the recording tracks by the magnetic head, the spin-torque oscillator is arranged as follows;

a second non-magnetic layer is formed on the free layer on the opposite side of the first nonmagnetic layer, and a second magnetic layer of an in-plane magnetization film is formed on the second non-magnetic layer on the opposite side of the free layer.

11. The apparatus according to claim 10, wherein the second magnetic layer is formed of an artificial antiferromagnetic material.

12. The apparatus according to claim 10, wherein the second non-magnetic layer is formed of a tunnel insulating film.