US4414287A
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Magnetic recording medium and its manufacture
Assignee: BASF SE
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Filing: 1982-06-29
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Granted: 1983-11-08
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Expires: 2002-06-29
Abstract
Abstract A magnetic recording medium comprising a non-magnetic base which is dimensionally stable at up to 300 DEG C., and an 0.03-0.4 mu m thick magnetically hard recording layer of an Sm-Co alloy, vacuum-deposited thereon, which layer possesses uniaxial magnetic anisotropy in the plane of the layer, and a process for the manufacture of this recording medium.
Inventors
- 👤 Eckhart Kneller
- 👤 Roland Koenig
- 👤 Eberhard Koester
- 👤 Werner Grau
- 👤 Dieter Mayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/12; H01F10/13; H01F10/133; H01F10/135; H01F10/137; H01F41/00; H01F41/14; H01F41/20; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12472; Y10T428/12493; Y10T428/12736; Y10T428/1275; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
80 words
A magnetic recording medium comprising a non-magnetic base which is dimensionally stable at up to 300° C., and an 0.03 to 0.4 μm thick, magnetically hard amorphous recording layer of an Sm-Co alloy, wherein the recording layer consists of an amorphous Sm-Co x alloy, where x is from 1 to 20, possesses uniaxial magnetic anisotropy in the plane of the layer and has a coercive force of from 10 to 100 kA/m and a squareness ratio of more than 0.9.
Claim 2
Dependent Claim
80 words
A magnetic recording medium comprising a non-magnetic base which is dimensionally stable at up to 300° C., and an 0.03 to 0.4 μm thick, magnetically hard amorphous recording layer of an Sm-Co alloy, wherein the recording layer consists of an amorphous Sm-Co x alloy, where x is from 1 to 20, possesses uniaxial magnetic anisotropy in the plane of the layer and has a coercive force of from 10 to 100 kA/m and a squareness ratio of more than 0.9.
Claim 3
Dependent Claim
20 words
A magnetic recording medium as set forth in claim 1, wherein the base is an aluminum or aluminum alloy disk.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-07 | 1987-05-09 | 1987-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-07 | 1991-05-09 | 1991-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-07 | 1995-05-09 | 1995-11-08 | $7700.00 | Window Closed / Lapsed |