IP Library Granted Patent US 8,603,651
Granted Patent B2
US 8,603,651 · App. 13/214,855 · Granted Dec 10, 2013

Perpendicular magnetic recording medium and magentic recording and reproducing apparatus

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Quick Facts
Patent No.
US 8,603,651
App. No.
13/214,855
Granted
Dec 10, 2013
Kind
B2
Abstract

A perpendicular magnetic recording medium that is excellent in terms of electromagnetic conversion characteristics and can achieve the demand for the recording density growth, and a magnetic recording and reproducing apparatus provided with the perpendicular magnetic recording medium are provided. The perpendicular magnetic recording medium has at least a backing layer, an underlayer, an intermediate layer, and a perpendicular magnetic recording layer sequentially laminated on a non-magnetic substrate, in which the backing layer includes at least a soft magnetic film having an amorphous structure; the underlayer includes a first underlayer and a second underlayer laminated from the non-magnetic substrate side; the first underlayer is an fcc-structured alloy layer including an fcc-structured element and a bcc-structured element, the second underlayer includes a NiW alloy; and the intermediate layer includes Ru or a Ru alloy.

Claims (15)

1. A perpendicular magnetic recording medium comprising: at least a backing layer, an underlayer, an intermediate layer, and a perpendicular magnetic recording layer sequentially laminated on a non-magnetic substrate,

wherein the backing layer includes at least a soft magnetic film having an amorphous structure,

the underlayer includes a first underlayer and a second underlayer laminated from the non-magnetic substrate side,

the first underlayer is an fcc-structured PdV alloy layer, wherein the amount of V included in the PdV alloy is within a range of 1 atom %,

the second underlayer includes a NiW alloy, and

the intermediate layer includes Ru or a Ru alloy.

2. A magnetic recording and reproducing apparatus provided with

the perpendicular magnetic recording medium according to claim 1 ; and

a single magnetic pole head that writes information on the perpendicular magnetic recording medium.

3. The media for perpendicular magnetic recording according to claim 1 ,

wherein the amount of V included in the PdV alloy is within a range of 40 atom % to 50 atom %.

4. The media for perpendicular magnetic recording according to claim 1 ,

wherein the thickness of the first underlayer is in a range of 1 nm to 5 nm.

5. The media for perpendicular magnetic recording according to claim 1 ,

wherein the thickness of the second underlayer is in a range of 2 nm to 20 nm.

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 Aug 24, 2011
From: TAKAHOSHI, HIDEAKI; UKAI, TAKAHIRO
To: SHOWA DENKO K.K.
Reel/Frame 026801/0239 →