IP Library Granted Patent US 8,717,710
Granted Patent B2
US 8,717,710 · App. 13/466,970 · Granted May 6, 2014

Corrosion-resistant bit patterned media (BPM) and discrete track media (DTM) and methods of production thereof

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Quick Facts
Patent No.
US 8,717,710
App. No.
13/466,970
Granted
May 6, 2014
Kind
B2
Abstract

In one embodiment, a magnetic recording medium includes a magnetic recording layer including a magnetic material characterized by having convex and concave portions, the convex portions acting as magnetic regions, a nonmagnetic material positioned within each concave portion of the magnetic material which act as nonmagnetic regions that separate the magnetic regions, an organic material layer which exhibits a corrosion-inhibiting characteristic with respect to cobalt or cobalt alloy positioned on a nonmagnetic region side of each concave portion, and an oxide layer and/or hydroxide layer positioned adjacent the organic material layer on a magnetic region side of each concave portion of the magnetic material. In another embodiment, the magnetic recording medium may be a patterned recording layer having a protective film, and the oxide layer and/or hydroxide layer may be positioned at least in defect portions of the protective film.

Claims (53)

1. A magnetic recording medium, comprising:

a magnetic recording layer comprising a magnetic material characterized by having convex and concave portions, the convex portions acting as magnetic regions;

a nonmagnetic material positioned within each concave portion of the magnetic material which act as nonmagnetic regions that separate the magnetic regions;

an organic material layer which exhibits a corrosion-inhibiting characteristic with respect to cobalt or cobalt alloy; and

an oxide layer and/or hydroxide layer,

wherein within each concave portion, the organic material layer is positioned between the magnetic material and the oxide and/or hydroxide layer.

2. The magnetic recording medium as recited in claim 1 , wherein the organic material layer and the oxide layer and/or hydroxide layer are only positioned on side walls of each concave portion of the magnetic material.

3. The magnetic recording medium as recited in claim 1 , wherein the organic material layer and the oxide layer and/or hydroxide layer are positioned on side walls and a bottom surface of each concave portion of the magnetic material.

4. The magnetic recording medium as recited in claim 1 , wherein the magnetic regions are in contact with and/or bonded with the oxide layer and/or hydroxide layer.

5. The magnetic recording medium as recited in claim 1 , further comprising:

an interlayer positioned below the recording layer;

a seed layer positioned below the interlayer; and

an adhesion layer positioned below the seed layer.

6. The magnetic recording medium as recited in claim 1 , wherein the oxide layer and/or hydroxide layer has a thickness of at least about 1 nm.

7. A magnetic data storage system, comprising:

at least one magnetic head;

a magnetic recording medium as recited in claim 1 ;

a drive mechanism for passing the magnetic medium over the at least one magnetic head; and

a controller electrically coupled to the at least one magnetic head for control operation of the at least one magnetic head.

8. A magnetic recording medium, comprising:

a patterned recording layer;

a protective film positioned above the patterned recording layer;

an oxide layer and/or hydroxide layer; and

an organic material layer which has a corrosion-inhibiting characteristic with respect to cobalt or cobalt alloy,

wherein in each defect portion of the protective film, the organic material layer is in direct contact with the oxide and/or hydroxide layer and positioned between the oxide and/or hydroxide layer and the patterned recording layer.

9. The magnetic recording medium as recited in claim 8 , further comprising:

an interlayer positioned below the patterned recording layer;

a seed layer positioned below the interlayer; and

an adhesion layer positioned below the seed layer.

10. The magnetic recording medium as recited in claim 8 , wherein the oxide layer and/or hydroxide layer has a thickness of at least about 1 nm.

11. A magnetic data storage system, comprising:

at least one magnetic head;

a magnetic recording medium as recited in claim 8 ;

a drive mechanism for passing the magnetic medium over the at least one magnetic head; and

a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head.

12. A method for producing a magnetic recording medium, the method comprising:

forming a magnetic material layer above a substrate;

transferring an uneven pattern to the magnetic material layer to form concave portions and convex portions, the convex portions being magnetic regions;

forming an oxide layer and/or hydroxide layer above the magnetic regions of the recording layer;

forming an organic material layer which exhibits a corrosion-inhibiting characteristic with respect to cobalt or cobalt alloy above the oxide layer and/or hydroxide layer; and

depositing a nonmagnetic material within the concave portions above the organic material layer to form nonmagnetic regions,

wherein within each concave portion, the organic material layer is positioned between the magnetic material and the oxide and/or hydroxide layer.

13. The method as recited in claim 12 , wherein the organic material layer and/or the oxide layer and/or hydroxide layer are formed by immersing the magnetic material layer in, or spraying the magnetic material layer with, a liquid comprising the corrosion-inhibiting organic material, an oxidant and a surfactant, or an organic material and an oxidant.

14. The method as recited in claim 13 , wherein the oxidant comprises at least one of: hydrogen peroxide, chloric acid, perchloric acid, persulfuric acid, nitric acid and salts thereof, and eerie ammonium nitrate.

15. The method as recited in claim 12 , wherein the organic material layer and/or the oxide layer and/or hydroxide layer are formed in the presence of ultrasonic waves.

16. The method as recited in claim 12 , wherein the corrosion-inhibiting organic material comprises a heterocyclic compound having nitrogen groups.

17. The method as recited in claim 16 , wherein the heterocyclic compound having nitrogen groups comprises at least one of: benzotriazole; 1,2,3-triazole; 1,2,3,4-tetrazole; 3-amino-1,2,4-triazole; nitro-1H-benzotriazole; carboxy benzotriazole; 5-methyl-benzotriazole; and uric acid.

18. The method as recited in claim 12 , wherein the surfactant comprises at least one of: an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a non-ionic surfactant.

19. The method as recited in claim 18 ,

wherein the anionic surfactant comprises at least one of: dodecyl sulfate, stearic acid, and toluenesulfonate,

wherein the cationic surfactant comprises at least one of: cetyltrimethyl ammonium salt and tetramethylammonium hydroxide,

wherein the amphoteric surfactant comprises lauryl betaine, and

wherein the non-ionic surfactant comprises at least one of: polyethylene glycol and polyvinyl alcohol.

Assignments (7)
PATENT COLLATERAL AGREEMENT - DDTL LOAN AGREEMENT Recorded Aug 21, 2023
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 067045/0156 →
PATENT COLLATERAL AGREEMENT - A&R LOAN AGREEMENT Recorded Aug 21, 2023
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 064715/0001 →
RELEASE OF SECURITY INTEREST AT REEL 052915 FRAME 0566 Recorded Feb 8, 2022
From: JPMORGAN CHASE BANK, N.A.
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 059127/0001 →
SECURITY INTEREST Recorded Feb 6, 2020
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A., AS AGENT
Reel/Frame 052915/0566 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 6, 2016
From: HGST NETHERLANDS B.V.
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 040826/0327 →
CHANGE OF NAME Recorded Oct 25, 2012
From: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
To: HGST NETHERLANDS B.V.
Reel/Frame 029341/0777 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 8, 2012
From: DAI, QING; MARCHON, BRUNO; MABUCHI, KATSUMI; AMO, MINA
To: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
Reel/Frame 028347/0630 →