IP Library Granted Patent US 10,699,737
Granted Patent B2
US 10,699,737 · App. 15/859,989 · Granted Jun 30, 2020

Magnetic recording medium and magnetic storage apparatus

Inventors: Takayuki Fukushima (Chiba, JP); Haruhisa Ohashi (Chiba, JP); Lei Zhang (Chiba, JP); Yuji Murakami (Chiba, JP); Hisato Shibata (Chiba, JP); Takehiro Yamaguchi (Chiba, JP); Tetsuya Kanbe (Chiba, JP)
Assignee: SHOWA DENKO K.K.
G11B5/65G11B5/66G11B5/7325G11B2005/0021
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Quick Facts
Patent No.
US 10,699,737
App. No.
15/859,989
Granted
Jun 30, 2020
Kind
B2
Abstract

A magnetic recording medium includes: a substrate; an underlayer; and a magnetic layer including an alloy having a L1 0 type crystal structure whose plane orientation is (001). The substrate, the underlayer, and the magnetic layer are stacked in this order. The underlayer includes a first underlayer. The first underlayer is a crystalline layer that includes a material containing Al, Ag, Cu, W, or Mo as a main component element and includes an oxide of the main component element, a content of the oxide of the main component element in the first underlayer being in a range of from 2 mol % to 30 mol %.

Claims (18)

1. A magnetic recording medium comprising:

a substrate;

an underlayer; and

a magnetic layer including an alloy having a L1 0 type crystal structure whose plane orientation is (001),

wherein the substrate, the underlayer, and the magnetic layer are stacked in this order,

wherein the underlayer includes a first underlayer,

wherein the first underlayer is a crystalline layer that includes a material containing Al, Ag, Cu, W, or Mo as a main component element and includes an oxide of the main component element, a content of the oxide of the main component element in the first underlayer being in a range of from 2 mol % to 30 mol %,

wherein the underlayer further includes a second underlayer provided between the substrate and the first underlayer,

wherein the second underlayer is a crystalline layer that contains, as a main component, an element having a crystal structure and a plane orientation equal to a crystal structure and a plane orientation of the main component element and that does not contain an oxide, and

wherein the second underlayer contains Ag, Cu, W, or Mo as the main component.

2. The magnetic recording medium according to claim 1 , wherein the first underlayer has a non-granular structure.

3. The magnetic recording medium according to claim 1 , further comprising:

a barrier layer between the underlayer and the magnetic layer,

wherein the barrier layer includes one or more compounds selected from a group consisting of MgO, TiO, NiO, TiN, TaN, HfN, NbN, ZrC, HfC, TaC, NbC, and TiC, and has a NaCl type structure.

4. The magnetic recording medium according to claim 1 , further comprising:

an orientation control layer between the substrate and the underlayer,

wherein the orientation control layer is a Cr layer having a BCC structure, an alloy layer containing Cr as a main component and having a BCC structure, or an alloy layer having a B2 structure.

5. A magnetic storage apparatus comprising the magnetic recording medium according to claim 1 .

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 Jan 2, 2018
From: FUKUSHIMA, TAKAYUKI; OHASHI, HARUHISA; ZHANG, LEI; MURAKAMI, YUJI; SHIBATA, HISATO; YAMAGUCHI, TAKEHIRO; KANBE, TETSUYA
To: SHOWA DENKO K.K.
Reel/Frame 044515/0695 →