US4749628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayered vertical magnetic recording medium
Assignee: International Business Machines Corp
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Filing: 1986-04-29
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Granted: 1988-06-07
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Expires: 2006-04-29
Abstract
Abstract A vertical magnetic recording medium is formed of multiple layers, each layer comprising a cobalt-platinum (CoPt) magnetic film formed on a hexagonal-close-packed (HCP) necleating film. The thickness of each CoPt film in each layer is sufficiently thin to assure that the film has perpendicular magnetic anisotropy. The magnetic properties of the multilayered magnetic film structure can be varied by varying the thickness of the individual films and the number of layers.
Inventors
- 👤 Richard H. Ahlert
- 👤 James K. Howard
- 👤 Grace S. Lim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:40
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/676; G11B5/678; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12806; Y10T428/12861
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
68 words
A medium for vertical magnetic recording comprising: a substrate; and a multilayered magnetic film structure formed on the substrate, each layer in the structure further comprising a nucleating film of titanium or an intermetallic compound of cobalt and tungsten (Co 3 W) and a magnetic film of a cobalt-platinum (CoPt) alloy formed on the nucleating film, the CoPt alloy film in each layer having substantially perpendicular magnetic anisotropy.
Claim 2
Independent Claim
68 words
A medium for vertical magnetic recording comprising: a substrate; and a multilayered magnetic film structure formed on the substrate, each layer in the structure further comprising a nucleating film of titanium or an intermetallic compound of cobalt and tungsten (Co 3 W) and a magnetic film of a cobalt-platinum (CoPt) alloy formed on the nucleating film, the CoPt alloy film in each layer having substantially perpendicular magnetic anisotropy.
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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) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |