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US5024903A
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Magnetic recording medium having a magnetic layer of a quaternary alloy
Assignee: Victor Company of Japan Ltd
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Filing: 1989-04-03
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Granted: 1991-06-18
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Expires: 2009-04-03
Abstract
Abstract A magnetic recording medium which comprises a non-magnetic substrate, a Cr undercoat layer formed on the substrate, and a quaternary alloy layer formed on the undercoat layer. The alloy layer consists of the following composition by atomic percent 1≦Cr≦18 2≦Ta≦9 73≦Co≦97 1≦Pt≦10 provided that the atomic percent of Cr, Ta and Co is 100 in total and the atomic percent of Pt is based on the total of Cr, Ta and Co.
Inventors
- 👤 Makoto Mizukami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:51
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; G11B5/653; G11B5/84; G11B5/851; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12875; Y10T428/12931
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
75 words
A magnetic recording medium suitable for high density recording, which comprises a non-magnetic substrate, a layer of Cr formed on the substrate and a layer of a CoCrTaPt quaternary alloy, said alloy consisting essentially of the following composition by atomic percent 1≦Cr≦18 2≦Ta≦9 73≦Co≦97 1≦Pt≦10 provided that the atomic percent of Cr, Ta and Co is 100 in total and the atomic percent of Pt is based on the total of Cr, Ta and Co.
Claim 2
Dependent Claim
75 words
A magnetic recording medium suitable for high density recording, which comprises a non-magnetic substrate, a layer of Cr formed on the substrate and a layer of a CoCrTaPt quaternary alloy, said alloy consisting essentially of the following composition by atomic percent 1≦Cr≦18 2≦Ta≦9 73≦Co≦97 1≦Pt≦10 provided that the atomic percent of Cr, Ta and Co is 100 in total and the atomic percent of Pt is based on the total of Cr, Ta and Co.
Claim 3
Dependent Claim
37 words
A magnetic recording medium according to claim 1, wherein said alloy consists essentially of 8≦Cr≦15, 3≦Ta≦7, 1.7≦Pt≦7.7 and the balance of Co in which the total content of Cr, Ta, Pt and Co is 100 atomic percent.
Claim 4
Dependent Claim
37 words
A magnetic recording medium according to claim 1, wherein said alloy consists essentially of 8.7≦Cr≦13, 3.5≦Ta≦6.5, 3.5≦Pt≦6.5 and the balance of Co in which the total content of Cr, Ta, Pt and Co is 100 atomic percent.
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) | 1994-06-17 | 1994-12-17 | 1995-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-17 | 1998-12-17 | 1999-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-17 | 2002-12-17 | 2003-06-18 | $7700.00 | Window Closed / Lapsed |