IP Library Granted Patent US 9,230,588
Granted Patent B2
US 9,230,588 · App. 14/326,555 · Granted Jan 5, 2016

Magnetic recording medium and magnetic storage apparatus

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Quick Facts
Patent No.
US 9,230,588
App. No.
14/326,555
Granted
Jan 5, 2016
Kind
B2
Abstract

A magnetic recording medium includes a substrate, a magnetic layer including an alloy having an L1 0 type crystal structure as a main component thereof, a plurality of underlayers arranged between the substrate and the magnetic layer, and a barrier layer made of a material having an NaCl structure. The plurality of underlayers include at least one crystalline underlayer including Mo as a main component thereof, and at least one of Si and C in a range of 1 mol % to 20 mol % and an oxide in a range of 1 vol % to 50 vol %. The barrier layer is provided between the magnetic layer and the at least one crystalline underlayer including Mo.

Claims (35)

1. A magnetic recording medium comprising:

a substrate;

a magnetic layer including an alloy having an L1 0 type crystal structure as a main component thereof;

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

a barrier layer made of a material having an NaCl structure,

wherein the plurality of underlayers include at least one crystalline underlayer including Mo as a main component thereof, and at least one of Si and C in a range of 1 mol % to 20 mol % and an oxide in a range of 1 vol % to 50 vol %, and

wherein the barrier layer is provided between the magnetic layer and the at least one crystalline underlayer including Mo.

2. The magnetic recording medium as claimed in claim 1 , wherein the at least one crystalline underlayer including Mo includes one or more elements selected from a group consisting of B 2 O 3 , SiO 2 , Cr 2 O 3 , Al 2 O 3 , Ta 2 O 5 , Nb 2 O 5 , ZrO 2 , Y 2 O 3 , CeO 2 , MnO, TiO 2 , TiO, ZnO, La 2 O 3 , NiO, FeO, and CoO.

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

the plurality of underlayers include an orientation control underlayer including Cr or Cr as a main component thereof and having a body centered cubic structure, and

the at least one crystalline underlayer including Mo is provided on the orientation control underlayer.

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

the plurality of underlayers include an orientation control underlayer having a B2 structure, and

the at least one crystalline underlayer including Mo is provided on the orientation control underlayer.

5. The magnetic recording medium as claimed in claim 1 , wherein the barrier layer is made of one or more compounds selected from a group consisting of MgO, TiO, NiO, TiN, TiC, TaN, HfN, NbN, ZrC, HfC, TaC, and NbC.

6. The magnetic recording medium as claimed in claim 1 , wherein the magnetic layer includes an CoPt alloy or an FePt alloy having the L1 0 type crystal structure as the main component thereof, and includes one or more materials selected from a group 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, B 2 O 3 , C, B, 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 includes

a substrate;

a magnetic layer including an alloy having an L1 0 type crystal structure as a main component thereof;

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

a barrier layer made of a material having an NaCl structure,

wherein the plurality of underlayers include at least one crystalline underlayer including Mo as a main component thereof, and at least one of Si and C in a range of 1 mol % to 20 mol % and an oxide in a range of 1 vol % to 50 vol %, and

wherein the barrier layer is provided between the magnetic layer and the at least one crystalline underlayer including Mo.

8. The magnetic storage apparatus as claimed in claim 7 , wherein the at least one crystalline underlayer including Mo, of the magnetic recording medium, includes one or more elements selected from a group consisting of B 2 O 3 , SiO 2 , Cr 2 O 3 , Al 2 O 3 , Ta 2 O 5 , Nb 2 O 5 , ZrO 2 , Y 2 O 3 , CeO 2 , MnO, TiO 2 , TiO, ZnO, La 2 O 3 , NiO, FeO, and CoO.

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

the plurality of underlayers of the magnetic recording medium include an orientation control underlayer including Cr or Cr as a main component thereof and having a body centered cubic structure, and

the at least one crystalline underlayer including Mo is provided on the orientation control underlayer.

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

the plurality of underlayers of the magnetic recording medium include an orientation control underlayer having a B2 structure, and

the at least one crystalline underlayer including Mo is provided on the orientation control underlayer.

11. The magnetic storage apparatus as claimed in claim 7 , wherein the barrier layer of the magnetic recording medium is made of one or more compounds selected from a group consisting of MgO, TiO, NiO, TiN, TiC, TaN, HfN, NbN, ZrC, HfC, TaC, and NbC.

12. The magnetic storage apparatus as claimed in claim 7 , wherein the magnetic layer of the magnetic recording medium includes an CoPt alloy or an FePt alloy having the L1 0 type crystal structure as the main component thereof, and includes one or more materials selected from a group 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, B 2 O 3 , C, B, 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 Jul 9, 2014
From: ZHANG, LEI; KANBE, TETSUYA; MURAKAMI, YUJI; NIWA, KAZUYA
To: SHOWA DENKO K.K.
Reel/Frame 033271/0140 →