Magnetic recording medium and manufacturing method therefor

• US 20060222905A1
• Filed: 03/20/2006
• Published: 10/05/2006
• Est. Priority Date: 04/05/2005
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Den, Toru, Yasui, Nobuhiro
• Granted Patent: US 7,586,830 B2
• Time in Patent Office: Days
• US Class Current: 428/836
• CPC Class Codes: G11B 5/65 characterised by its composition G11B5/66 takes precedence
• CPC Class Codes: G11B 5/851 Coating a support with a magnetic layer by sputtering
• CPC Class Codes: G11B 5/855 Coating only part of a support with a magnetic layer

Abstract

There is provided a novel magnetic recording medium which less damages the recording layer and of which recording tracks are fully magnetically spaced apart and manufacturing method therefor. The present invention provides the magnetic recording medium having a recording layer on a member with concave and convex portions, wherein the recording layer is provided on the concave and convex portions, and the recording layers on the concave and convex portions are different in magnetic properties with each other.

Claims

1. A magnetic recording medium having a recording layer on a member with a concavo-convex portion,

wherein the recording layer has cylindrical magnetic particles,

the recording layer is provided on the concave and convex portions, and the recording layers on the concave and convex portions are different in magnetic properties from each other.

2. The magnetic recording medium according to claim 1, wherein, for the magnetic properties of the recording layer on the convex and concave portions, the recording layer on the convex portion is higher in remanence and coercivity than the recording layer on the concave portion.

3. The magnetic recording medium according to claim 1, wherein a granular structure is formed on the recording layer at least on the convex portion.

4. The magnetic recording medium according to claim 1, wherein the magnetic recording medium satisfies at least one of the following:

the cylindrical magnetic particle in the granular structure in the recording layer on the concave portion is smaller in average diameter than the cylindrical magnetic particle in the granular structure in the recording layer on the convex portion, and

the cylindrical magnetic particle in the recording layer on the convex portion is parallel with the direction vertical to a substrate, while at least a part of the cylindrical magnetic particles in the recording layer on the concave portion deviates from parallel.

5. The magnetic recording medium according to claim 1, wherein the recording layer on the concave portion is comprised of an amorphous structure in which the existence of particles are substantially not recognized.

6. The magnetic recording medium according to claim 1, wherein the recording layer on the member is substantially flat.

7. The magnetic recording medium according to claim 1, wherein the concave portion is 50 nm or less in depth D and 100 nm or less in width Wg at the surface of a material of the concave portion.

8. The magnetic recording medium according to claim 7, wherein the width Wg is less than the double of the depth D.

9. The magnetic recording medium according to claim 1, wherein the convex portion is 10 nm or more to 300 nm or less in width Wt.

10. The magnetic recording medium according to claim 9, wherein the recording layer on the convex portion is 30 nm or less in thickness.

11. A method of manufacturing the magnetic recording medium according to claim 1 comprising the steps of:

introducing the member with the concave and convex portions into a sputtering device,

subjecting the member as a substrate to the application of a DC bias voltage, whereby a magnetic material is sputtered to form a granular structure with cylindrical magnetic particles at least on the convex portion.

12. A method of manufacturing the magnetic recording medium according to claim 1 comprising the steps of:

introducing the member with the concave and convex portions into a sputtering device,

subjecting the member as a substrate to the application of a DC bias voltage, whereby AlSi is sputtered to form a granular structure with cylindrical Al particles at least on the convex portion, and then

removing Al portions to fill a magnetic material.

13. A magnetic recording reproduction device using the magnetic recording medium according to claim 1.

14. An information processing device using the magnetic recording reproduction device according to claim 13.