US3787237A
Expired / Lapsed
US
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Method of making a thin film having a high coercive field
Assignee: Commissariat à l'Énergie Atomique et Aux Énergies Alternatives
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Filing: 1971-06-22
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Granted: 1974-01-22
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Expires: 1991-06-22
Abstract
Abstract An isotropic thin film having a high coercive field for use as a magnetic memory, and comprising a non-ferromagnetic substrate, at least one chromium layer having a thickness smaller than 10,000 A overlying said substrate and at least one cobalt layer having a thickness smaller than 1,000 A overlying the chromium layer. In a process for the fabrication of the thin film, the chromium layer or layers and the cobalt layer or layers are deposited on the non-ferromagnetic substrate by evaporation under a vacuum.
Inventors
- 👤 G Grunberg
- 👤 I Melnick
- 👤 J Lazzari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:48
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/06; C23C14/14; B; B82; B82Y; B82Y25/00; H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/12; H01F10/13; H01F10/132; H01F10/16; H01F10/32; H01F10/324; H01F41/00; H01F41/14; H01F41/20; G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/656; G11B5/66; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/926; Y10S428/9265; Y10S428/928; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12806; Y10T428/12826; Y10T428/12847; Y10T428/12854
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
38 words
The process accrording to claim 1, wherein a plurality of chromium layers and a plurality of cobalt layers are alternately coated on said substrate, each of said chromium layers being arranged alternately with each of said cobalt layers.
Claim 2
Dependent Claim
30 words
The process according to claim 1, wherein the respective deposition rates of said layers are between 10 and 20 A per second and between 0.5 and 1 A per second.
Claim 3
Dependent Claim
17 words
The process according to claim 1, wherein the rate of cobalt deposition is lower than 1 A/sec.
Claim 4
Dependent Claim
27 words
The process according to claim 1, wherein the temperature of the substrate at the time of evaporation of the cobalt is within the range of 300to 340*C.
Claim 5
Dependent Claim
17 words
The process of claim 1, wherein the rate of chromium deposition is about 10 to 20 A/sec.
Claim 6
Dependent Claim
17 words
The process of claim 1, wherein the rate of cobalt deposition is about 0.5 to 1 A/sec.
Claim 7
Dependent Claim
16 words
The process of claim 1, wherein each cobalt layer has a thickness less than 200 A.
Claim 8
Dependent Claim
18 words
The process of claim 1, wherein each chromium layer has a thickness of about 50 to 10,000 A.
Claim 9
Dependent Claim
21 words
The process of claim 1, wherein the thickness of the cobalt layer is about double the thickness of the chromium layer.
References Cited (Backward Citations)
US3549417A
Cited
US3702263A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |