IP Library Granted Patent US 12,217,779
Granted Patent B2
US 12,217,779 · App. 18/146,647 · Granted Feb 4, 2025

Method of manufacturing magnetic recording medium

Inventors: Yoshitaka Aono (Chiba, JP); Takahiro Ukai (Chiba, JP); Takanao Ebisawa (Chiba, JP); Kazuya Niwa (Chiba, JP); Takayuki Konno (Chiba, JP)
Assignee: Resonac Hard Disk Corporation
G11B5/667G11B5/672G11B5/851
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Quick Facts
Patent No.
US 12,217,779
App. No.
18/146,647
Granted
Feb 4, 2025
Kind
B2
Abstract

A method of manufacturing a magnetic recording medium including: forming a diffusion preventing layer, wherein the magnetic recording medium includes a non-magnetic substrate; an underlayer; a perpendicular magnetic layer; the diffusion preventing layer; and a protective layer, wherein the perpendicular magnetic layer has a multi-layer structure, the perpendicular magnetic layer includes an uppermost layer and at least one layer other than the uppermost layer, the uppermost layer including Co or Fe in magnetic particles, and the at least one layer other than the uppermost layer including an oxide, the diffusion preventing layer is provided between the perpendicular magnetic layer and the protective layer, and the diffusion preventing layer includes at least one component selected from a group consisting of Si, Ti, Cr, B, and Ru, or either a carbide, an oxide, or both, of the at least one component.

Claims (13)

1. A method of manufacturing a magnetic recording medium comprising:

forming a diffusion preventing layer by a reactive sputtering method, an ion implantation method, or an ion etching method, wherein

the magnetic recording medium includes a non-magnetic substrate; an underlayer; a perpendicular magnetic layer; the diffusion preventing layer; and a protective layer, wherein

the underlayer, the perpendicular magnetic layer, the diffusion preventing layer, and the protective layer are layered on the non-magnetic substrate in this order,

the perpendicular magnetic layer has a multi-layer structure,

the perpendicular magnetic layer includes an uppermost layer and at least one layer other than the uppermost layer, the uppermost layer including Co or Fe in magnetic particles, and the at least one layer other than the uppermost layer including an oxide,

the diffusion preventing layer is provided between the perpendicular magnetic layer and the protective layer,

the diffusion preventing layer includes at least one component selected from a group consisting of Si, Ti, Cr, B, and Ru, or either a carbide, an oxide, or both, of the at least one component,

the diffusion preventing layer includes carbon, and

a content of carbon in the diffusion preventing layer is 20 at % or more.

2. The method of manufacturing a magnetic recording medium according to claim 1 , wherein the diffusion preventing layer is formed by the ion implantation method, and the diffusion preventing layer is formed using a gas containing an organosilicon compound as a source of Si.

3. The method of manufacturing a magnetic recording medium according to claim 1 , wherein a total content of Si, Ti, Cr, B, and Ru contained in the diffusion preventing layer is 0.5 at % to 10 at % .

4. The method of manufacturing a magnetic recording medium according to claim 1 , wherein a total content of Si, Ti, Cr, B, and Ru contained in the diffusion preventing layer is 2 at % to 4 at % .

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 15, 2024
From: RESONAC CORPORATION
To: RESONAC HARD DISK CORPORATION
Reel/Frame 069167/0673 →
DECLARATION OF SUCCESSION Recorded Oct 31, 2023
From: SHOWA DENKO K.K.
To: RESONAC CORPORATION
Reel/Frame 065413/0308 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 27, 2022
From: AONO, YOSHITAKA; UKAI, TAKAHIRO; EBISAWA, TAKANAO; NIWA, KAZUYA; KONNO, TAKAYUKI
To: SHOWA DENKO K.K.
Reel/Frame 062210/0865 →
Priority Claims (1)
JP 2021-016196 · Feb 4, 2021 · national
Continuity (2)
Division 17649588 · Feb 1, 2022
Related Publication 20230131031A1 · Apr 27, 2023
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