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US4640755A
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Method for producing magnetic medium
Assignee: Sony Corp
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Filing: 1984-12-06
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Granted: 1987-02-03
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Expires: 2004-12-06
Abstract
Abstract A method for producing a magnetic medium which includes the steps of sputtering a magnetic material containing iron onto a substrate in an atmosphere of argon gas mixed with nitrogen gas and depositing a magnetic film on the substrate. The nitrogen is preferably present in an amount of 10 to 10000 ppm and serves to increase the saturation intensity of magnetization. The preferred version of the method consists in jointly sputtering a rare earth metal and an iron-cobalt.
Inventors
- 👤 Noboru Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:16
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/0021; C23C14/0036; G; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B11/10589; G11B11/10591; G11B5/00; G11B5/84; G11B5/851
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
60 words
A method for producing a magnetic medium comprising the steps of: sputtering a magnetic material consisting of Fe-Co alone or Tb-FeCo onto a substrate in an atmosphere of argon gas mixed with nitrogen gas in a sufficient amount to increase the saturation intensity of magnetization of said material and forming a magnetic film on said substrate while rotating said substrate.
Claim 2
Independent Claim
60 words
A method for producing a magnetic medium comprising the steps of: sputtering a magnetic material consisting of Fe-Co alone or Tb-FeCo onto a substrate in an atmosphere of argon gas mixed with nitrogen gas in a sufficient amount to increase the saturation intensity of magnetization of said material and forming a magnetic film on said substrate while rotating said substrate.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein said nitrogen is present in an amount of 10 to 10,000 ppm.
Claim 4
Dependent Claim
20 words
A method according to claim 1 wherein sputtering takes place from a plurality of targets, one of which is Tb.
Claim 5
Dependent Claim
15 words
A method according to claim 3 wherein one of said targets is FeCo alloy plate.
Claim 6
Dependent Claim
19 words
A method according to claim 4 wherein said FeCo alloy plate has the composition Fe 95-50 Co 5-50 .
Claim 7
Dependent Claim
19 words
A method according to claim 4 wherein said FeCo alloy plate has the composition Fe 95-70 Co 5-30 .
Claim 8
Dependent Claim
22 words
A method according to claim 1 wherein said atmosphere of argon is at a pressure of 10 -2 to 10 -3 Torr.
References Cited (Backward Citations)
US3303116A
Cited
US4367257A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-02 | 1990-08-04 | 1991-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-02 | 1994-08-04 | 1995-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-02 | 1998-08-04 | 1999-02-03 | $7700.00 | Window Closed / Lapsed |