Magnetic recording medium

Abstract

A perpendicular magnetic recording medium including: a substrate; a perpendicular magnetic recording layer disposed over the substrate; a soft magnetic underlayer disposed between the substrate and the perpendicular magnetic recording layer; a shunting layer disposed under the soft magnetic underlayer; and an isolation layer disposed between the soft magnetic underlayer and the shunting layer and providing magnetic isolation between the shunting layer and the other layers disposed over the shunting layer are provided. The shunting layer is magnetically separated from the other magnetic layers disposed over the shunting layer, and shunts a magnetic field generated by the magnetic domain walls of the soft magnetic underlayer such that the magnetic field cannot reach a magnetic head, thereby increasing a signal-to-noise ratio (SNR).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.

The above and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

FIG. 1 is a cross-sectional view of a perpendicular magnetic recording medium according to an exemplary embodiment of the present invention;

FIG. 2 is a cross-sectional view of a perpendicular magnetic recording medium according to another exemplary embodiment of the present invention;

FIG. 3 is a perspective view illustrating the function of a shunting layer of a perpendicular magnetic recording medium, according to the exemplary embodiments of the present invention;

FIG. 4 is a cross-sectional view of a perpendicular magnetic recording medium according still another exemplary embodiment of the present invention;

FIG. 5 is a cross-sectional view of a perpendicular magnetic recording medium according yet another exemplary embodiment of the present invention;

FIG. 6 is a cross-sectional view of a perpendicular magnetic recording medium according a further exemplary embodiment of the present invention:

FIG. 7 is a diagram of an experimental configuration including a related art perpendicular magnetic recording medium structure (a) and a perpendicular magnetic recording medium structure (b) according to an exemplary embodiment of the present invention for comparing SNRs thereof; and

FIGS. 8A and 8B illustrate simulation results illustrating noises of the related art structure and the structure according to an exemplary embodiment of the present invention.

Claims

1. A perpendicular magnetic recording medium comprising: a substrate;a perpendicular magnetic recording layer disposed over the substrate;a soft magnetic underlayer disposed between the substrate and the perpendicular magnetic recording layer;a shunting layer disposed under the soft magnetic underlayer; andan isolation layer disposed between the soft magnetic underlayer and the shunting layer and providing magnetic isolation between the shunting layer and the other layers disposed over the shunting layer.

2. The perpendicular magnetic recording medium of claim 1, wherein the shunting layer is formed of one selected from CoZrNb, NiFe, CoFe, and CoFeB.

3. The perpendicular magnetic recording medium of claim 1, further comprising a ferromagnetic layer disposed between the soft magnetic under layer and the shunting layer.

4. The perpendicular magnetic recording medium of claim 2, further comprising a ferromagnetic layer disposed between the soft magnetic underlayer and the shunting layer.

5. The perpendicular magnetic recording medium of claim 3, wherein the soft magnetic underlayer has a multi-layered structure in which unit soft magnetic underlayers are stacked and a spacer is disposed between adjacent unit soft magnetic underlayers.

6. The perpendicular magnetic recording medium of claim 4, wherein the soft magnetic underlayer has a multi-layered structure in which unit soft magnetic underlayers are stacked and a spacer is disposed between adjacent unit soft magnetic underlayers.

7. The perpendicular magnetic recording medium of claim 1, wherein the soft magnetic underlayer has a multi-layered structure in which unit soft magnetic underlayers are stacked and a spacer is disposed between adjacent unit soft magnetic underlayers.

8. The perpendicular magnetic recording medium of claim 2, wherein the soft magnetic underlayer has a multi-layered structure in which unit soft magnetic underlayers are stacked and a spacer is disposed between adjacent unit soft magnetic underlayers.

9. The perpendicular magnetic recording medium of claim 1, further comprising a soft magnetic alignment layer disposed between the soft magnetic underlayer and the isolation layer.

10. The perpendicular magnetic recording medium of claim 2, further comprising a soft magnetic alignment layer disposed between the soft magnetic underlayer and the isolation layer.

11. The perpendicular magnetic recording medium of claim 9, further comprising a perpendicular alignment layer disposed between the perpendicular magnetic recording layer and the soft magnetic underlayer.

12. The perpendicular magnetic recording medium of claim 10, further comprising a perpendicular alignment layer disposed between the perpendicular magnetic recording layer and the soft magnetic underlayer.

13. The perpendicular magnetic recording medium of claim 1, further comprising a perpendicular alignment layer disposed between the perpendicular magnetic recording layer and the soft magnetic underlayer.