Perpendicular magnetic recording medium and method of manufacturing same

Patent metadata

Field	Value
Publication number	US-9659592-B2
Application number	US-201213817141-A
Country	US
Kind code	B2
Filing date	May 1, 2012
Priority date	Jun 3, 2011
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

A perpendicular magnetic recording medium exhibits reduced noise and improved performance in such measures as SN ratio, and can realize high magnetic recording densities. In the perpendicular magnetic recording medium, at least a first nonmagnetic intermediate layer, second nonmagnetic intermediate layer, and magnetic recording layer are stacked in order on a nonmagnetic substrate. The first nonmagnetic intermediate layer is formed from a CoCrRuW alloy, and the second nonmagnetic intermediate layer is formed from an Ru-base alloy.

First claim

The invention claimed is:

1. A perpendicular magnetic recording medium comprising:
a nonmagnetic substrate;
a first nonmagnetic intermediate layer above the nonmagnetic substrate;
a second nonmagnetic intermediate layer on the first nonmagnetic intermediate layer; and
a magnetic recording layer on the second nonmagnetic intermediate layer;
wherein the first nonmagnetic intermediate layer is formed from a CoCrRuW alloy, and the second nonmagnetic intermediate layer is formed from an Ru-base alloy; and
wherein the CoCrRuW alloy has a Cr content of 14.5 at % or higher and 25.5 at % or lower, a Ru content of 4.5 at % or higher and 20.5 at % or lower, and a W content of 4.5 at % or higher and 8.5 at % or lower, and wherein a remainder of the CoCrRuW alloy is Co.

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

3. The perpendicular magnetic recording medium according to claim 1 , wherein a film thickness of the first nonmagnetic intermediate layer is from 5 to 14 nm.

4. A method of manufacturing a perpendicular magnetic recording medium,
the method comprising a step of stacking, in order on a nonmagnetic substrate, a first nonmagnetic intermediate layer, a second nonmagnetic intermediate layer, and a magnetic recording layer,
wherein the first nonmagnetic intermediate layer is formed from a CoCrRuW alloy, and the second nonmagnetic intermediate layer is formed from an Ru-base alloy and
wherein the CoCrRuW alloy has a Cr content of 14.5 at % or higher and 25.5 at % or lower, a Ru content of 4.5 at % or higher and 20.5 at % or lower, and a W content of 4.5 at % or higher and 8.5 at % or lower, and wherein a remainder of the CoCrRuW alloy is Co.

5. The manufacturing method according to claim 4 , wherein the magnetic recording layer includes a granular structure.

Assignees

• Ataka Toyoji
• Takenoiri Shunji
• Watanabe Sadayuki
• Oyama Hirohisa
• Hozumi yasuaki
• Takahashi Satoshi
• Fuji Electric Co Ltd

Inventors

• Ataka Toyoji
• Takenoiri Shunji
• Watanabe Sadayuki
• Oyama Hirohisa
• Hozumi yasuaki
• Takahashi Satoshi

Classifications

• G11B5/8404

  manufacturing base layers · CPC title

• G11B5/851

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

• G11B5/7325

  Physics · mapped topic

• G11B5/73

  Base layers {, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer} · CPC title

• G11B5/85

  Coating a support with a magnetic layer by vapour deposition · CPC title