US4603091A
Expired / Lapsed
US
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Recording medium for perpendicular magnetization
Assignee: Alps Alpine Co Ltd
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Filing: 1984-11-05
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Granted: 1986-07-29
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Expires: 2004-11-05
Abstract
Abstract A magnetic recording medium for perpendicular magnetization includes a base of a nonmagnetic material, a first magnetic layer of a soft magnetic material on a surface of the base, a second magnetic layer having perpendicular anisotropy on a surface of the first magnetic layer, the second magnetic layer being magnetized in a transverse direction thereof. The second magnetic layer is composed of a three-element alloy of cobalt, chromium, and tantalum, cobalt being a main component with chromium and tantalum added thereto.
Inventors
- 👤 Koichi Mukasa
- 👤 Takashi Hatanai
- 👤 Keishi Nakashima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:22
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12771; Y10T428/12806; Y10T428/12819; Y10T428/12826; Y10T428/12847; Y10T428/12854; Y10T428/12861; Y10T428/12937
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
90 words
A magnetic recording medium for perpendicular magnetization, consisting essentially of: (a) a base of a nonmagnetic material; (b) a first magnetic layer of a soft magnetic material on a surface of said base; (c) a second magnetic layer having perpendicular anisotropy on a surface of said first magnetic layer, said second magnetic layer being magnetized in a transverse direction thereof; and (d) said second magnetic layer consisting of a three-element alloy of cobalt, chromium, and tantalum, with the range of atomic % of cobalt 75-82, chromium 18-25, and tantalum 0.1-1.1.
Claim 2
Dependent Claim
90 words
A magnetic recording medium for perpendicular magnetization, consisting essentially of: (a) a base of a nonmagnetic material; (b) a first magnetic layer of a soft magnetic material on a surface of said base; (c) a second magnetic layer having perpendicular anisotropy on a surface of said first magnetic layer, said second magnetic layer being magnetized in a transverse direction thereof; and (d) said second magnetic layer consisting of a three-element alloy of cobalt, chromium, and tantalum, with the range of atomic % of cobalt 75-82, chromium 18-25, and tantalum 0.1-1.1.
References Cited (Backward Citations)
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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) | 1989-07-28 | 1990-01-27 | 1990-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-28 | 1994-01-27 | 1994-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-28 | 1998-01-27 | 1998-07-29 | $7700.00 | Window Closed / Lapsed |