IP Library Granted Patent US 8,988,828
Granted Patent B2
US 8,988,828 · App. 14/316,950 · Granted Mar 24, 2015

Magnetic recording medium and magnetic storage apparatus

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Quick Facts
Patent No.
US 8,988,828
App. No.
14/316,950
Granted
Mar 24, 2015
Kind
B2
Abstract

A magnetic recording medium includes a substrate, a magnetic layer including an alloy having an L1 0 type crystal structure, and a plurality of underlayers arranged between the substrate and the magnetic layer. At least one of the plurality of underlayers is a soft magnetic underlayer formed by an alloy having a hexagonal close packed (hcp) structure and including Co metal or Co as its main component, with a (11•0) plane oriented parallel to a surface of the substrate.

Claims (31)

1. A magnetic recording medium comprising:

a substrate;

a magnetic layer including an alloy having an L1 0 type crystal structure; and

a plurality of underlayers arranged between the substrate and the magnetic layer,

wherein at least one of the plurality of underlayers is a soft magnetic underlayer formed by an alloy having a hexagonal close packed (hcp) structure and including Co metal or Co as its main component, with a (11•0) plane oriented parallel to a surface of the substrate.

2. The magnetic recording medium as claimed in claim 1 , wherein the soft magnetic underlayer includes at least one kind of element selected from a group of elements consisting of Fe, Ni, Cr, Mn, V, Ru, Re, Pt, and Pd.

3. The magnetic recording medium as claimed in claim 1 , wherein

the plurality of underlayers include a predetermined underlayer formed by an alloy having a body centered cubic (bcc) structure and including Cr metal or Cr as its main component, and

the soft magnetic underlayer is formed on the predetermined underlayer.

4. The magnetic recording medium as claimed in claim 3 , wherein the alloy of the predetermined underlayer includes at least one kind of element selected from a group of elements consisting of Mn, V, Ti, Mo, W, Nb, and Ru.

5. The magnetic recording medium as claimed in claim 1 , wherein

the plurality of underlayers include a predetermined underlayer formed by an NiAl alloy or an RuAl alloy having a B2 structure, and

the soft magnetic underlayer is formed on the predetermined underlayer.

6. The magnetic recording medium as claimed in claim 1 , wherein the magnetic layer includes a FePt alloy having an L0 1 type crystal structure, or a CoPt alloy having an L0 1 type crystal structure, and at least one kind of material selected from a group of materials consisting of SiO 2 , TiO 2 , Cr 2 O 3 , Al 2 O 3 , Ta 2 O 5 , ZrO 2 , Y 2 O 3 , CeO 2 , MnO, TiO, ZnO, C, B, B 2 O 3 , and BN.

7. A magnetic storage apparatus comprising:

a magnetic recording medium; and

a head configured to write information on and read information from the magnetic recording medium,

wherein the magnetic recording medium comprises:

a substrate;

a magnetic layer including an alloy having an L1 0 type crystal structure; and

a plurality of underlayers arranged between the substrate and the magnetic layer,

wherein at least one of the plurality of underlayers is a soft magnetic underlayer formed by an alloy having a hexagonal close packed (hcp) structure and including Co metal or Co as its main component, with a (11•0) plane oriented parallel to a surface of the substrate.

8. The magnetic storage apparatus as claimed in claim 7 , wherein the soft magnetic underlayer of the magnetic recording medium includes at least one kind of element selected from a group of elements consisting of Fe, Ni, Cr, Mn, V, Ru, Re, Pt, and Pd.

9. The magnetic storage apparatus as claimed in claim 7 , wherein

the plurality of underlayers of the magnetic recording medium include a predetermined underlayer formed by an alloy having a body centered cubic (bcc) structure and including Cr metal or Cr as its main component, and

the soft magnetic underlayer is formed on the predetermined underlayer.

10. The magnetic storage apparatus as claimed in claim 9 , wherein the alloy of the predetermined underlayer includes at least one kind of element selected from a group of elements consisting of Mn, V, Ti, Mo, W, Nb, and Ru.

11. The magnetic storage apparatus as claimed in claim 7 , wherein

the plurality of underlayers of the magnetic recording medium include a predetermined underlayer formed by an NiAl alloy or an RuAl alloy having a B2 structure, and

the soft magnetic underlayer is formed on the predetermined underlayer.

12. The magnetic storage apparatus as claimed in claim 7 , wherein the magnetic layer of the magnetic recording medium includes a FePt alloy having an L0 1 type crystal structure, or a CoPt alloy having an L0 1 type crystal structure, and at least one kind of material selected from a group of materials consisting of SiO 2 , TiO 2 , Cr 2 O 3 , Al 2 O 3 , Ta 2 O 5 , ZrO 2 , Y 2 O 3 , CeO 2 , MnO, TiO, ZnO, C, B, B 2 O 3 , and BN.

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 Jun 27, 2014
From: KANBE, TETSUYA; NIWA, KAZUYA; MURAKAMI, YUJI; ZHANG, LEI
To: SHOWA DENKO K.K.
Reel/Frame 033196/0605 →