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US4707756A
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Perpendicular magnetic recording medium
Assignee: HGST Japan Ltd
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Filing: 1985-04-10
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Granted: 1987-11-17
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Expires: 2005-04-10
Abstract
Abstract Disclosed is a perpendicular magnetic recording medium wherein an underlayer made of a material containing Si and/or Ge as its principal ingredient is deposited on a substrate, and a perpendicular magnetic film made of a Co-based alloy is deposited on the underlayer. With the perpendicular magnetic recording medium, the perpendicular magnetic film has an enhanced degree of C-axis orientation, and the bond strength between the perpendicular magnetic film and the substrate is also enhanced when the substrate is non-metallic.
Inventors
- 👤 Masaaki Futamoto
- 👤 Yukio Honda
- 👤 Yasutaro Uesaka
- 👤 Kazuetsu Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:33
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; G11B5/127; G11B5/1278; G11B5/66; G11B5/672; G11B5/73; G11B5/7368; G11B5/7377; G11B5/739; G11B5/73911; G11B5/73921; G11B5/73923; G11B5/73927; G11B2005/0002; G11B2005/0026; G11B2005/0029; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12674
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
60 words
A perpendicular magnetic recording medium comprising a substrate, an underlayer which is made of a material containing as its principal ingredient at least one element selected from the group consisting of Si and Ge and which is deposited on said substrate, and a perpendicular magnetic film which is made of a Co-based alloy and which is deposited on said underlayer.
Claim 2
Dependent Claim
60 words
A perpendicular magnetic recording medium comprising a substrate, an underlayer which is made of a material containing as its principal ingredient at least one element selected from the group consisting of Si and Ge and which is deposited on said substrate, and a perpendicular magnetic film which is made of a Co-based alloy and which is deposited on said underlayer.
Claim 3
Dependent Claim
25 words
A perpendicular magnetic recording medium according to claim 1, wherein a thickness of said underlayer is at least 100 Å and at most 1 μm.
Claim 4
Dependent Claim
25 words
A perpendicular magnetic recording medium according to claim 2, wherein a thickness of said underlayer is at least 150 Å and at most 1000 Å.
Claim 5
Dependent Claim
58 words
A perpendicular magnetic recording medium according to claim 1, wherein said underlayer is made of a material in which at least one element other than Si and Ge is added in such a range of amount that any structure other than a diamond structure and an amorphous structure does not appear in a crystal structure of said underlayer.
Claim 6
Dependent Claim
58 words
A perpendicular magnetic recording medium according to claim 2, wherein said underlayer is made of a material in which at least one element other than Si and Ge is added in such a range of amount that any structure other than a diamond structure and an amorphous structure does not appear in a crystal structure of said underlayer.
Claim 7
Dependent Claim
58 words
A perpendicular magnetic recording medium according to claim 3, wherein said underlayer is made of a material in which at least one element other than Si and Ge is added in such a range of amount that any structure other than a diamond structure and an amorphous structure does not appear in a crystal structure of said underlayer.
Claim 8
Dependent Claim
30 words
A perpendicular magnetic recording medium according to claim 1, wherein at least that surface of said substrate on which said underlayer is formed is made of a soft magnetic material.
Claim 9
Dependent Claim
30 words
A perpendicular magnetic recording medium according to claim 2, wherein at least that surface of said substrate on which said underlayer is formed is made of a soft magnetic material.
Claim 10
Dependent Claim
30 words
A perpendicular magnetic recording medium according to claim 3, wherein at least that surface of said substrate on which said underlayer is formed is made of a soft magnetic material.
Claim 11
Dependent Claim
27 words
A perpendicular magnetic recording medium according to claim 1, wherein said Co-based alloy is selected from the group consisting of Co-Cr, Co-V, Co-Mo, Co-O, Co-Cr-Rh and Co-Cr-Ru.
Claim 12
Dependent Claim
17 words
A perpendicular magnetic recording medium according to claim 1, wherein said Co-based alloy is a Co-Cr alloy.
Claim 13
Dependent Claim
31 words
A perpendicular magnetic recording medium according to claim 4, wherein said at least one element other than Si and Ge is selected from the group consisting of Ti, Zr and B.
Claim 14
Dependent Claim
29 words
A perpendicular magnetic recording medium according to claim 1, wherein said substrate is made of a material selected from the group consisting of polyimide, polyethylene terephthalate and quartz glass.
Claim 15
Dependent Claim
15 words
A perpendicular magnetic recording medium according to claim 11, wherein said underlayer consists of Ge.
Claim 16
Dependent Claim
31 words
A perpendicular magnetic recording medium comprising a substrate, an underlayer made of Ge deposited on said substrate, and a perpendicular magnetic film made of a Co-Cr alloy deposited on said underlayer.
Claim 17
Dependent Claim
31 words
A perpendicular magnetic recording medium comprising a substrate, an underlayer made of Ge deposited on said substrate, and a perpendicular magnetic film made of a Co-Cr alloy deposited on said underlayer.
Claim 18
Dependent Claim
25 words
A perpendicular magnetic recording medium according to claim 15, wherein a thickness of said underlayer is at least 100 Å and at most 1 μm.
Claim 19
Dependent Claim
25 words
A perpendicular magnetic recording medium according to claim 15, wherein a thickness of said underlayer is at least 150 Å and at most 1000 Å.
Claim 20
Dependent Claim
30 words
A perpendicular magnetic recording medium according to claim 15, wherein at least that surface of said substrate on which said underlayer is formed is made of a soft magnetic material.
Claim 21
Dependent Claim
29 words
A perpendicular magnetic recording medium according to claim 15, wherein said substrate is made of a material selected from the group consisting of polyimide, polyethylene terephthalate and quartz glass.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-16 | 1991-05-18 | 1991-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-16 | 1995-05-18 | 1995-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-16 | 1999-05-18 | 1999-11-17 | $7700.00 | Window Closed / Lapsed |