IP Library Granted Patent US 11,244,700
Granted Patent B2
US 11,244,700 · App. 16/169,065 · Granted Feb 8, 2022

Magnetic recording medium, sputtering target, sputtering target manufacturing method, and magnetic storage apparatus

Inventors: Katsumi Murofushi (Chiba, JP); Yoshitaka Ishibashi (Chiba, JP); Takayuki Fukushima (Chiba, JP); Kazuya Niwa (Chiba, JP); Lei Zhang (Chiba, JP); Yuji Murakami (Chiba, JP); Hisato Shibata (Chiba, JP); Takehiro Yamaguchi (Chiba, JP); Chen Xu (Chiba, JP); Tetsuya Kanbe (Chiba, JP); Tomoo Shige (Chiba, JP)
Assignee: SHOWA DENKO K.K.
G11B5/65G11B5/656G11B5/72G11B5/82C08L61/28G11B5/851
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Quick Facts
Patent No.
US 11,244,700
App. No.
16/169,065
Granted
Feb 8, 2022
Kind
B2
Abstract

A magnetic recording medium includes a substrate, an underlayer provided on the substrate, and a magnetic layer provided on the underlayer and having a L1 0 structure and a (001) orientation. The magnetic layer has a granular structure in which an organic compound having a methylene skeleton or a methine skeleton is arranged at grain boundaries of magnetic grains.

Claims (27)

1. A magnetic recording medium comprising:

a substrate;

an underlayer provided on the substrate; and

a magnetic layer, provided on the underlayer, and having a L1 0 structure and a (001) orientation caused by the underlayer,

wherein the magnetic layer has a granular structure in which an organic compound having a first skeleton or a second skeleton is arranged at grain boundaries of magnetic grains,

wherein the first skeleton refers to skeletons represented by

and the second skeleton refers to skeletons represented by

and

wherein the organic compound is a nitrogen-including organic compound selected from a group consisting of melamine resin, and a compound including an amide linkage or an urethane linkage.

2. The magnetic recording medium as claimed in claim 1 , wherein a content of the organic compound having the first skeleton or the second skeleton in the magnetic layer is 0.5 vol % or greater and 40 vol % or less.

3. The magnetic recording medium as claimed in claim 1 , wherein the magnetic layer has a thickness of 1 nm or greater and 7 nm or less.

4. The magnetic recording medium as claimed in claim 1 , wherein the magnetic grains include an FePt alloy or a CoPt alloy.

5. The magnetic recording medium as claimed in claim 3 , wherein the magnetic grains include an FePt alloy or a CoPt alloy.

6. A magnetic storage apparatus comprising:

a magnetic recording medium according to claim 1 ; and

a magnetic head configured to record signals on and reproduce signals from the magnetic recording medium according to a heat assisted magnetic recording method.

7. The magnetic recording medium as claimed in claim 1 , wherein the organic compound having the first skeleton or the second skeleton has a thermal conductivity of 0.7 W/(m·k) or lower.

8. A magnetic recording medium comprising:

a substrate;

an underlayer provided on the substrate; and

a magnetic layer provided on the underlayer and having a L1 0 structure and a (001) orientation caused by the underlayer,

wherein the magnetic layer has a granular structure in which a nitrogen-including organic compound having a first skeleton or a second skeleton is arranged at grain boundaries of magnetic grains,

wherein the first skeleton refers to skeletons represented by

and the second skeleton refers to skeletons represented by

wherein a content of the nitrogen-including organic compound having the first skeleton or the second skeleton in the magnetic layer is 0.5 vol % or greater and 40 vol % or less, and

wherein the nitrogen-including organic compound is polyimide.

9. The magnetic recording medium as claimed in claim 8 , wherein the nitrogen-including organic compound having the first skeleton or the second skeleton has a thermal conductivity of 0.7 W/(m·k) or lower.

Assignments (4)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 15, 2024
From: RESONAC CORPORATION
To: RESONAC HARD DISK CORPORATION
Reel/Frame 069167/0673 →
CHANGE OF ADDRESS Recorded Feb 14, 2024
From: RESONAC CORPORATION
To: RESONAC CORPORATION
Reel/Frame 066599/0037 →
CHANGE OF NAME Recorded Jun 23, 2023
From: SHOWA DENKO K.K.
To: RESONAC CORPORATION
Reel/Frame 064082/0513 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 24, 2018
From: MUROFUSHI, KATSUMI; ISHIBASHI, YOSHITAKA; FUKUSHIMA, TAKAYUKI; NIWA, KAZUYA; ZHANG, LEI; MURAKAMI, YUJI; SHIBATA, HISATO; YAMAGUCHI, TAKEHIRO; XU, CHEN; KANBE, TETSUYA; SHIGE, TOMOO
To: SHOWA DENKO K.K.
Reel/Frame 047292/0227 →