US5316631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for fabricating a magnetic recording medium
Assignee: Victor Company of Japan Ltd
•
Filing: 1992-08-11
•
Granted: 1994-05-31
•
Expires: 2012-08-11
Abstract
Abstract A magnetic recording medium which comprises, on a substrate, a Cr undercoat layer and a Co alloy thin film formed on the substrate in this order. The coercive force of the medium is significantly improved by incorporating oxygen either in the Cr undercoat layer or in the Co alloy thin film.
Inventors
- 👤 Toshio Ando
- 👤 Toshikazu Nishihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:58
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/0021; C23C14/0036; C23C14/06; C23C14/14; C23C14/18; C23C14/185; G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; G11B5/73; G11B5/7368; G11B5/7373; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12931
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
94 words
A method for fabricating a magnetic recording medium which comprises forming a Cr undercoat layer on a substrate and further forming a Co alloy thin film on the undercoat layer by sputtering, wherein said undercoat layer is formed by sputtering in an atmosphere of a mixed gas of argon and oxygen at a total pressure of from 10 to 20 mTorr and at a partial pressure of oxygen of from 1 to 20% based on the total pressure whereby from 4 to 50 atomic percent of the oxygen is incorporated in the undercoat layer.
Claim 2
Independent Claim
94 words
A method for fabricating a magnetic recording medium which comprises forming a Cr undercoat layer on a substrate and further forming a Co alloy thin film on the undercoat layer by sputtering, wherein said undercoat layer is formed by sputtering in an atmosphere of a mixed gas of argon and oxygen at a total pressure of from 10 to 20 mTorr and at a partial pressure of oxygen of from 1 to 20% based on the total pressure whereby from 4 to 50 atomic percent of the oxygen is incorporated in the undercoat layer.
Claim 3
Dependent Claim
26 words
A method according to claim 1, wherein the partial pressure of oxygen is in the range of from 5 to 10% based on the total pressure.
References Cited (Backward Citations)
GB1379360A
Cited
US4661418A
Cited
JPS5958804A
Cited
JPS5961105A
Cited
US4548871A
Cited
JPS6083218A
Cited
US4743348A
Cited
US4711810A
Cited
JPS61105721A
Cited
JPS61115244A
Cited
US4987039A
Cited
US4900397A
Cited
US5066552A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-30 | 1997-11-29 | 1998-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-30 | 2001-11-29 | 2002-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-30 | 2005-11-29 | 2006-05-31 | $7700.00 | Window Closed / Lapsed |