EP0053811A1
Expired / Lapsed
EP
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Magnetic recording media
Assignee: Panasonic Holdings Corp
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Filing: 1981-12-03
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Granted: —
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Expires: 2001-12-03
Abstract
Abstract A magnetic recording medium of the type in which a thin magnetic film mainly comprising Co; Co and Ni; Co and Cr; or Co, Ni and Cr is deposited on a nonmagnetic substrate (1); the thin magnetic film comprises a surface layer adjacent to the native oxidized layer at surface and a deep layer below it; and the average oxygen content in the surface layer is greater than that in the deep layer.
Inventors
- 👤 Ryuji Sugita
- 👤 Toshiaki Kunieda
- 👤 Hideki Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 00:06
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/14; H01F41/20; G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/72; G11B5/84; G11B5/851; H01F10/00; H01F10/08; H01F10/10; H01F10/18; H01F10/26; H01F10/265; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12583; Y10T428/1259; Y10T428/12639; Y10T428/12646; Y10T428/1266
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
84 words
A magnetic recording medium of the type in which a thin magnetic film whose major component comprises Co; Co and Ni; Co and Cr; or Co, Ni and Cr is deposited over a substrate made of a nonmagnetic material, characterized in that said thin magnetic film consists of a surface layer adjacent to the native oxidized layer at surface and a deep layer below said surface layer; and the average oxygen content in said surface layer is higher than that in said deep layer.
Claim 2
Dependent Claim
84 words
A magnetic recording medium of the type in which a thin magnetic film whose major component comprises Co; Co and Ni; Co and Cr; or Co, Ni and Cr is deposited over a substrate made of a nonmagnetic material, characterized in that said thin magnetic film consists of a surface layer adjacent to the native oxidized layer at surface and a deep layer below said surface layer; and the average oxygen content in said surface layer is higher than that in said deep layer.
Claim 3
Dependent Claim
33 words
A magnetic recording medium as set forth in Claim 1 further characterized.in that the thickness of said surface layer is equal to about one third of the thickness of said thin magnetic film.
Claim 4
Dependent Claim
25 words
A magnetic recording medium as set forth in Claim 1 further characterized in that a plurality of thin magnetic films are overlaid over said substrate.
Claim 5
Dependent Claim
36 words
A magnetic recording medium as set forth in Claim 2 further characterized in that the average oxygen content in said surface layer is in excess of 1.2 times as high as that in said deep layer.
Claim 6
Dependent Claim
38 words
A magnetic recording medium as set forth in Claim 1 further characterized in that the number of oxygen atoms in said thin magnetic film is higher than 25% as compared with the total number of atoms of metals.
Claim 7
Dependent Claim
31 words
A magnetic recording medium as set forth in Claim 1 further characterized in that said thin magnetic film is deposited by the vacuum evaporation process in the atmosphere containing the oxygen.
Claim 8
Dependent Claim
33 words
A magnetic recording medium as set forth in Claim 1 further characterized in that said thin magnetic film is deposited in the atmosphere containing the oxygen by an oblique incidence vacuum evaporation process.
References Cited (Backward Citations)
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