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US4743348A
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Magnetic medium for horizontal magnetization recording and method for making same
Assignee: Victor Company of Japan Ltd
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Filing: 1987-08-18
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Granted: 1988-05-10
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Expires: 2007-08-18
Abstract
Abstract A magnetic medium for horizontal magnetization recording which comprises a non-magnetic substrate and a magnetic recording film formed on at least one side of the substrate, is described. The magnetic recording film consists essentially of an amorphous Co-Cr alloy containing from 5 to 15 atomic percent of oxygen atom. A method for making the above type of medium is also described in which the magnetic film is vapor deposited under conditions of a partial pressure of oxygen gas of 1×10 -3 to 3×10 -3 Torr., and a sputtering rate of from 0.05 to 0.15 μm/minute.
Inventors
- 👤 Toshio Ando
- 👤 Toshikazu Nishihara
- 👤 Akihiro Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:29
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; G11B5/84; G11B5/851; G11B5/658; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
71 words
A method for making a magnetic medium for horizontal magnetization recording which comprises subjecting a Co-Cr target to vapor deposition in an atmosphere of oxygen gas with a partial pressure of 1×10 -3 to 3×10 -3 Torr. at a sputtering rate of about 0.05 to 0.15 μm/minute to form, on a non-magnetic substrate, a magnetic recording film of an amorphous Co-Cr alloy containing from 5 to 15 atomic percent of oxygen.
Claim 2
Independent Claim
71 words
A method for making a magnetic medium for horizontal magnetization recording which comprises subjecting a Co-Cr target to vapor deposition in an atmosphere of oxygen gas with a partial pressure of 1×10 -3 to 3×10 -3 Torr. at a sputtering rate of about 0.05 to 0.15 μm/minute to form, on a non-magnetic substrate, a magnetic recording film of an amorphous Co-Cr alloy containing from 5 to 15 atomic percent of oxygen.
Claim 3
Dependent Claim
16 words
A method according to claim 1, wherein said sputtering rate is from 0.09 to 0.12 μm/minute.
Claim 4
Dependent Claim
38 words
A method according to claim 1, wherein the relation between the partial pressure of oxygen as expressed by Po 2 Torr., and the sputtering rate as expressed by SR μm/minute satisfies the following inequality 1×10.sup.-2 Torr./(μm/minute)≦Po.sub.2 /SR≦3×10.sup.-2 Torr./(μm/minute).
Claim 5
Dependent Claim
26 words
A method according to claim 1, wherein the temperature of said substrate on the sputtering is in the range of from room temperature to 300° C.
Claim 6
Dependent Claim
29 words
A method according to claim 1, wherein the ratio of an oxygen partial pressure to the total pressure in the atmosphere is in the range of 2 to 7:100.
Claim 7
Dependent Claim
14 words
A magnetic medium for horizontal magnetization recording produced by the method of claim 1.
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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) | 1991-05-10 | 1991-11-09 | 1992-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-10 | 1995-11-09 | 1996-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-10 | 1999-11-09 | 2000-05-10 | $7700.00 | Window Closed / Lapsed |