US4835069A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Tohoku Steel Co Ltd
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Filing: 1984-08-03
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Granted: 1989-05-30
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Expires: 2004-08-03
Abstract
Abstract A magnetic recording medium having a magnetic layer formed by a thin film deposition method, said magnetic layer comprising Fe as the principal component together with Co, Ni, and Cr, further containing at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Mo, W, Cu, Mn and Sb.
Inventors
- 👤 Takeshi Sawada
- 👤 Akira Shinmi
- 👤 Hiroshi Takagi
- 👤 Kenji Suzuki
- 👤 Fumio Kishi
- 👤 Susumu Kozuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:34
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
52 words
A magnetic recording medium having a thin ferromagnetic corrosion resistant metallic film formed by an oblique incidence deposition method characterized in that a composition of the thin ferromagnetic metal film layer is represented by the formula: (Fe.sub.1-x Co.sub.x).sub.1-(a+b+c) Ni.sub.a Cr.sub.b Sb.sub.c wherein the weight ratios being 0<X≦0.5, 0.05≦a≦0.2, 0.01≦b≦0.15, 0.001≦c≦0.1 and b+c≦0.2.
Claim 2
Dependent Claim
52 words
A magnetic recording medium having a thin ferromagnetic corrosion resistant metallic film formed by an oblique incidence deposition method characterized in that a composition of the thin ferromagnetic metal film layer is represented by the formula: (Fe.sub.1-x Co.sub.x).sub.1-(a+b+c) Ni.sub.a Cr.sub.b Sb.sub.c wherein the weight ratios being 0<X≦0.5, 0.05≦a≦0.2, 0.01≦b≦0.15, 0.001≦c≦0.1 and b+c≦0.2.
Claim 3
Dependent Claim
48 words
The magnetic recording medium according to claim 1 wherein the composition of the thin ferromagnetic film is 1-6 wt % of Cr, 1-8 wt% of Sb, 3-12 wt% of the sum total of Cr and Sb, 7-14 wt% of Ni, 20-30 wt% of Co, the remainder of Fe.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |