US4714641A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferromagnetic films for high density recording and methods of production
Assignee: Varian Semiconductor Equipment Associates Inc
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Filing: 1985-03-04
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Granted: 1987-12-22
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Expires: 2005-03-04
Abstract
Abstract A ferromagnetic film for magnetic recording comprises a copper substrate having particles of iron and iron oxides dispersed in the surface layer of the copper. The particles have maximum dimensions in the range between 50 and 500 Angstroms. The ferromagnetic film can be formed by ion implantation of iron ions into the copper substrate followed by heat treatment to permit growth of ferromagnetic particles to the desired size. As an alternative to ion implantation, the iron can be deposited on the copper substrate by sputtering or evaporation and mixed with the copper by ion beam mixing.
Inventors
- 👤 Bernhard F. Cordts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:07
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/06; C23C14/14; C23C14/16; C23C14/165; C23C14/22; C23C14/48; C23C14/58; C23C14/5806; C23C14/5826; C23C14/5833; C23C14/584; C23C14/5893; G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70605; G11B5/70615; G11B5/70626; G11B5/70642; G11B5/73; G11B5/739; G11B5/73911; G11B5/73917; G11B5/84; G11B5/85; G11B5/851; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12021; Y10T428/12028; Y10T428/12049; Y10T428/12056; Y10T428/12063; Y10T428/12097; Y10T428/12458; Y10T428/12465; Y10T428/12486; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12903; Y10T428/12917; Y10T428/12986
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
47 words
A ferromagnetic film comprising: a metallic substrate material having low solubility for a selected ferromagnetic material; and a plurality of particles of said selected ferromagnetic material in the surface layer of said substrate, said particles having a maximum dimension in the range between 50 and 500 Angstroms.
Claim 2
Dependent Claim
47 words
A ferromagnetic film comprising: a metallic substrate material having low solubility for a selected ferromagnetic material; and a plurality of particles of said selected ferromagnetic material in the surface layer of said substrate, said particles having a maximum dimension in the range between 50 and 500 Angstroms.
Claim 3
Dependent Claim
18 words
A ferromagnetic film as defined in claim 1 wherein selected ferromagnetic material includes iron and oxides of iron.
Claim 4
Dependent Claim
13 words
A ferromagnetic film as defined in claim 2 wherein said substrate comprises copper.
Claim 5
Dependent Claim
16 words
A ferromagnetic film as in claim 1 wherein said selected ferromagnetic material includes oxides of iron.
References Cited (Backward Citations)
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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) | 1990-12-21 | 1991-06-22 | 1991-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-21 | 1995-06-22 | 1995-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-21 | 1999-06-22 | 1999-12-22 | $7700.00 | Window Closed / Lapsed |