Magnetic recording medium having a recording layer with a diffraction peak of magnetic atoms

Patent metadata

Field	Value
Publication number	US-9299378-B2
Application number	US-201514666581-A
Country	US
Kind code	B2
Filing date	Mar 24, 2015
Priority date	Mar 31, 2014
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

A magnetic recording medium includes a base material which has flexibility, a lower coating layer, and a recording layer, in which, in X-ray diffraction peaks, a value of Δθ 50 where a diffraction peak of magnetic atoms which are included in the recording layer is measured by a locking curve method is 5° or more to less than 10°.

First claim

The invention is claimed as follows:

1. A magnetic recording medium comprising:
a base material which has flexibility;
a lower coating layer; and
a recording layer,
wherein, in X-ray diffraction peaks, a value of Δθ 50 where a diffraction peak of magnetic atoms which are included in the recording layer is measured by a locking curve method is from 5° to 10°,
wherein an arithmetic average roughness Ra of an interface between the base material and a lower layer of the lower coating layer is from 0.4 nm to 1.0 nm.

2. The magnetic recording medium according to claim 1 , further comprising a soft magnetic underlayer,
wherein an arithmetic average roughness Ra of an interface between the soft magnetic underlayer and the lower coating layer is 0.4 nm or more to 1.0 nm or less.

3. The magnetic recording medium according to claim 2 ,
wherein the soft magnetic underlayer includes an antiparallel coupled structure.

4. The magnetic recording medium according to claim 2 , further comprising a layer provided between the base material and the soft magnetic underlayer, wherein the layer includes a Ti alloy.

5. The magnetic recording medium according to claim 1 , further comprising:
an intermediate layer which is provided between the lower coating layer and the recording layer,
wherein, in X-ray diffraction peaks, a value of Δθ 50 where a diffraction peak of atoms which are included in the intermediate layer is measured by a locking curve method is 4° or more to 9° or less.

6. The magnetic recording medium according to claim 5 ,
wherein the intermediate layer includes a plurality of layers with a same composition and wherein the plurality of layers are provided under different film-forming conditions.

7. The magnetic recording medium according to claim 5 ,
wherein the intermediate layer includes Ru.

8. The magnetic recording medium according to claim 1 ,
wherein the lower coating layer includes Ti or Ni.

9. The magnetic recording medium according to claim 1 ,
wherein an average thickness of the recording layer is 10 nm or more.

10. The magnetic recording medium according to claim 1 ,
wherein the recording layer includes a perpendicular recording layer.

11. The magnetic recording medium according to claim 1 ,
wherein the recording layer includes a granular structure.

12. The magnetic recording medium according to claim 11 ,
wherein the recording layer includes an alloy including Co, Cr, and Pt and an oxide including Si oxide.

13. The magnetic recording medium according to claim 11 ,
wherein an average particle diameter of crystal particles which are included in the recording layer is from 6 nm to 8 nm.

14. The magnetic recording medium according to claim 1 , further comprising a cap layer.

15. The magnetic recording medium according to claim 1 ,
wherein a coercive force Hc is from 3000 Oe to 5500 Oe, and
a squareness ratio Rs is 85% or more.

16. The magnetic recording medium according to claim 1 ,
wherein the lower coating layer and the recording layer are film-formed by a sputtering method.

17. The magnetic recording medium according to claim 1 ,
wherein the lower coating layer and the recording layer are film-formed by a roll to roll method.

18. The magnetic recording medium according to claim 1 ,
wherein the lower coating layer includes a Ti alloy including Ti and Cr, and the lower coating layer is an amorphous.

19. The magnetic recording medium according to claim 18 ,
wherein the Ti alloy further includes oxygen and wherein a ratio of oxygen in the Ti alloy is equal to or less than 15 atomic %.

Assignees

• Sony Corp

Inventors

• Sekiguchi Noboru
• Tachibana Junichi
• Endo Tetsuo
• Ozaki Tomoe
• Terui Hikaru

Classifications

• G11B5/851

  Coating a support with a magnetic layer by sputtering · CPC title

• G11B5/64

  comprising only the magnetic material without bonding agent · CPC title

• G11B5/738

  Physics · mapped topic

• G11B5/667 Primary

  including a soft magnetic layer · CPC title

• G11B5/7325

  Physics · mapped topic