US5106828A
Expired / Lapsed
US
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Method for fabricating superconductors by sol-gel process
Assignee: Philips North America LLC
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Filing: 1987-07-20
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Granted: 1992-04-21
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Expires: 2007-07-20
Abstract
Abstract Superconducting oxides in the A, B, Cu oxide ternary system, where A is yttrium or a rare earth and B is an alkaline earth, are formed as thin films on a substrate by a sol-gel technique.
Inventors
- 👤 Rameshwar N. Bhargava
- 👤 William N. Osborne
- 👤 Walter K. Zwicker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:19
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0296; H10N60/0324; C; C01; C01G; C01G3/00; C01G3/006; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4504; C04B35/4508; C23; C23C; C23C18/00; C23C18/02; C23C18/12; C23C18/1204; C23C18/1208; C23C18/1216; C23C18/125; C23C18/1254; C23C18/1279; C23C18/1283; C01P; C01P2002/00; C01P2002/70; C01P2002/72; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/734; Y10S505/735
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
81 words
A method for producing a copper oxide based superconducting oxide composition, the method comprising: 1) forming a sol from a solution of hydrolyzable alkoxides in a volatile non-polar solvent, the alkoxides being precursors of the desired oxide constituents and being present in the stoichiometric proportions needed to yield the desired superconducting composition, 2) gelling the sol by hydrolysis and polymerization of the alkoxides, and 3) firing the gel in an oxygen-containing atmosphere to convert the gel to a crystalline superconducting oxide.
Claim 2
Independent Claim
81 words
A method for producing a copper oxide based superconducting oxide composition, the method comprising: 1) forming a sol from a solution of hydrolyzable alkoxides in a volatile non-polar solvent, the alkoxides being precursors of the desired oxide constituents and being present in the stoichiometric proportions needed to yield the desired superconducting composition, 2) gelling the sol by hydrolysis and polymerization of the alkoxides, and 3) firing the gel in an oxygen-containing atmosphere to convert the gel to a crystalline superconducting oxide.
Claim 3
Dependent Claim
14 words
The method of claim 1 in which the non-polar volatile solvent is an alcohol.
Claim 4
Dependent Claim
17 words
The method of claim 1 in which gelling is carried out in the presence of water vapor.
Claim 5
Dependent Claim
22 words
The method of claim 1 in which the gel is fired at a temperature of from about 700 to 1,000 degrees C.
Claim 6
Dependent Claim
36 words
The method of claim 4 in which the firing is carried out in two steps, a first step being carried out in an air atmosphere and a second step being carried out in an oxygen atmosphere.
Claim 7
Dependent Claim
27 words
The method of claim 4 in which following firing, the film is heated in an oxygen atmosphere at a temperature of from about 400° to 900° C.
Claim 8
Dependent Claim
59 words
The method of claim 1 in which the oxide composition is within the ternary oxide system for A, B and copper oxides, where A is at least one cation selected from the group consisting of yttrium and the rare earths, and B is at least one cation selected from the group of alkaline earths consisting of barium and strontium.
Claim 9
Dependent Claim
12 words
The method of claim 7 in which the composition additionally contains fluorine.
Claim 10
Dependent Claim
24 words
The method of claim 7 in which the solution of alkoxides is formed by adding A, B and Cu precursor compounds to the solvent.
Claim 11
Dependent Claim
18 words
The method of claim 9 in which the solvent is butanol and the copper compound is copper cyclohexanebutyrate.
Claim 12
Dependent Claim
14 words
The method of claim 10 in which the A and B compounds are butoxides.
Claim 13
Dependent Claim
10 words
The method of claim 11 in which A is yttrium.
Claim 14
Dependent Claim
10 words
The method of claim 11 in which B is barium.
Claim 15
Dependent Claim
23 words
The method of claim 7 in which the ratio of the precursors in solution results in a molar ratio of A:B:Cu of 1:2:3.
Claim 16
Dependent Claim
21 words
The method of claim 1 in which prior to gelling, the sol is formed into a thin film on a substrate.
References Cited (Backward Citations)
US4606906A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-04-21 | 1995-10-21 | 1996-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-21 | 1999-10-21 | 2000-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-21 | 2003-10-21 | 2004-04-21 | $7700.00 | Window Closed / Lapsed |