Patent US6693004B1 successfully refreshed from Google Patents.
US5135907A
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Manufacture of high purity superconducting ceramic
Assignee: General Atomics Corp
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Filing: 1988-12-01
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Granted: 1992-08-04
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Expires: 2008-12-01
Abstract
Abstract A method for the manufacture of superconducting polycrystalline ceramic materials by the decomposition of a mixture of isopropoxides.
Inventors
- 👤 Khodabakhsh S. Mazdiyasni
- 👤 Debra J. Treacy
- 👤 Barry W. McQuillan
- 👤 Frederick H. Elsner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:18
CPC Classifications
C; C01; C01G; C01G3/00; C01G3/006; B; B82; B82Y; B82Y30/00; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4504; H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; C01P; C01P2002/00; C01P2002/70; C01P2002/72; C01P2002/76; C01P2004/00; C01P2004/60; C01P2004/62; C01P2004/64; C01P2006/00; C01P2006/60; C01P2006/80; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/734; Y10S505/735; Y10S505/737; Y10S505/738
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
248 words
A method for the manufacture of a ceramic powder that exhibits superconducting properties when cooled to an appropriate temperature between about 90° K. and about 40° K., said ceramic having the formula MM' 2 Cu 3 O 6 .5-8, where M is yttrium, a member of the lanthanide rare earth metal series, or mixtures thereof and M' is selected from barium, strontium and mixtures thereof and where up to about two thirds of Cu may be replaced by Ni, and having an average particle size of between about 2 and about 500 nm and a purity in excess of 99.9% comprising: a) preparing a homogeneous solution of the alkoxides of M, M' and Cu in an alcohol solvent, the molar concentrations of said alkoxides being selected to provide the desired ceramic stoichiometry; b) hydrolytically decomposing said alkoxides by controlled hydrolysis with triply distilled deionized water at a pH above about 7 thereby forming a particulate precipitate of the hydroxides of M, M' and Cu having a particle size of between about 2 and about 500 nm; c) separating the hydroxide precipitate; d) calcining the hydroxide precipitate at a temperature of between about 300° C. and about 600° C. for a period of between about 15 and about 60 minutes to remove volatiles and to convert the hydroxides to oxides; and e) roasting the calcined oxides at a temperature of between about 800° C. and about 1100° C. for a period of between about 1 and about 5 hours.
Claim 2
Independent Claim
248 words
A method for the manufacture of a ceramic powder that exhibits superconducting properties when cooled to an appropriate temperature between about 90° K. and about 40° K., said ceramic having the formula MM' 2 Cu 3 O 6 .5-8, where M is yttrium, a member of the lanthanide rare earth metal series, or mixtures thereof and M' is selected from barium, strontium and mixtures thereof and where up to about two thirds of Cu may be replaced by Ni, and having an average particle size of between about 2 and about 500 nm and a purity in excess of 99.9% comprising: a) preparing a homogeneous solution of the alkoxides of M, M' and Cu in an alcohol solvent, the molar concentrations of said alkoxides being selected to provide the desired ceramic stoichiometry; b) hydrolytically decomposing said alkoxides by controlled hydrolysis with triply distilled deionized water at a pH above about 7 thereby forming a particulate precipitate of the hydroxides of M, M' and Cu having a particle size of between about 2 and about 500 nm; c) separating the hydroxide precipitate; d) calcining the hydroxide precipitate at a temperature of between about 300° C. and about 600° C. for a period of between about 15 and about 60 minutes to remove volatiles and to convert the hydroxides to oxides; and e) roasting the calcined oxides at a temperature of between about 800° C. and about 1100° C. for a period of between about 1 and about 5 hours.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein the alcohol is isopropyl alcohol.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein the hydrolytic decomposition is carried out at or near room temperature.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein the oxides are roasted in the presence of oxygen.
Claim 6
Independent Claim
23 words
The method of any one of claims 1 to 4 wherein the ceramic has the formula YBa 2 Cu 3 O 6 .5-8.
Claim 7
Independent Claim
23 words
The method of any one of claims 1 to 4 wherein the ceramic has the formula YBa 2 Cu 3 O 6 .5.
Claim 8
Dependent Claim
18 words
The method of claim 1 wherein the particulate oxides are pressed into a discrete shape prior to roasting.
Claim 9
Independent Claim
216 words
A method for the manufacture of a ceramic monolith that exhibits superconducting properties when cooled to an appropriate temperature between about 90° K. and about 40° K., said ceramic having the formula MM' 2 Cu 3 O 6 .5-8, where M is yttrium, a member of the lanthanide rare earth metal series, or mixture thereof and M' is selected from barium, strontium and mixtures thereof and where up to about two thirds of Cu may be replaced by Ni comprising: a) preparing a homogeneous solution of the alkoxides of M, M' and Cu in an alcohol solvent, the molar concentrations of said akloxides being selected to provide the desired ceramic stoichiometry; b) hydrolytically decomposing said alkoxides by controlled hydrolysis with triply distilled deionized water at a pH of less than about 7 forming a sol of the hydroxides of M, M' and Cu; c) forming the sol into a monolith; d) calcining the monolith at a temperature of between about 300° C. and about 600° C. for a period of between about 15 and about 60 minutes to remove volatiles and to convert the hydroxides to oxides; and e) roasting the calcined oxides at a temperature of between about 800° C. and about 1100° C. for a period of between about 1 to about 5 hours.
Claim 10
Independent Claim
216 words
A method for the manufacture of a ceramic monolith that exhibits superconducting properties when cooled to an appropriate temperature between about 90° K. and about 40° K., said ceramic having the formula MM' 2 Cu 3 O 6 .5-8, where M is yttrium, a member of the lanthanide rare earth metal series, or mixture thereof and M' is selected from barium, strontium and mixtures thereof and where up to about two thirds of Cu may be replaced by Ni comprising: a) preparing a homogeneous solution of the alkoxides of M, M' and Cu in an alcohol solvent, the molar concentrations of said akloxides being selected to provide the desired ceramic stoichiometry; b) hydrolytically decomposing said alkoxides by controlled hydrolysis with triply distilled deionized water at a pH of less than about 7 forming a sol of the hydroxides of M, M' and Cu; c) forming the sol into a monolith; d) calcining the monolith at a temperature of between about 300° C. and about 600° C. for a period of between about 15 and about 60 minutes to remove volatiles and to convert the hydroxides to oxides; and e) roasting the calcined oxides at a temperature of between about 800° C. and about 1100° C. for a period of between about 1 to about 5 hours.
Claim 11
Dependent Claim
11 words
The method of claim 8 wherein the alcohol is isopropyl alcohol.
Claim 12
Dependent Claim
17 words
The method of claim 8 wherein the hydrolytic decomposition is carried out at or near room temperature.
Claim 13
Dependent Claim
16 words
The method of claim 8 wherein the calcined monolith is roasted in the presence of oxygen.
Claim 14
Independent Claim
23 words
The method of any one of claims 8 to 11 wherein the ceramic has the formula YBa 2 Cu 3 O 6 .5-8.
Claim 15
Independent Claim
23 words
The method of any one of claims 8 to 11 wherein the ceramic has the formula YBa 2 Cu 3 O 6 .5.
Claim 16
Dependent Claim
14 words
The method of claim 8 wherein the monolith is fibers spun from the sol.
Claim 17
Dependent Claim
20 words
The method of claim 8 wherein the monolith is a substrate coated with one or more layers of the sol.
Claim 18
Dependent Claim
19 words
The method of claim 8 wherein the sol is converted to a gel prior to formation of the monolith.
Claim 19
Dependent Claim
16 words
The method of claim 16 wherein the monolith is formed by molding or casting the gel.
Claim 20
Independent Claim
88 words
A method for the manufacture of homogenous solutions of M, M' and Cu alkoxides, wherein M is yttrium, a member of the lanthanide rare earth metal series, or mixtures thereof, M' is selected from barium, strontium and mixtures thereof and where a portion of Cu may be replaced by Ni, comprising: a) reacting a Cu alkoxide with an organic amine, and b) admixing the obtained complex with solutions of M and M' alkoxides in a solvent selected from the group consisting of alcohols, organic amines and mixtures thereof.
Claim 21
Independent Claim
88 words
A method for the manufacture of homogenous solutions of M, M' and Cu alkoxides, wherein M is yttrium, a member of the lanthanide rare earth metal series, or mixtures thereof, M' is selected from barium, strontium and mixtures thereof and where a portion of Cu may be replaced by Ni, comprising: a) reacting a Cu alkoxide with an organic amine, and b) admixing the obtained complex with solutions of M and M' alkoxides in a solvent selected from the group consisting of alcohols, organic amines and mixtures thereof.
Claim 22
Dependent Claim
21 words
The method of claim 18 wherein said organic amine reacted with said Cu alkoxide is a primary or secondary aliphatic amine.
Claim 23
Dependent Claim
12 words
The method of claim 19 wherein said aliphatic amine is an alkanolamine.
Claim 24
Dependent Claim
12 words
The method of claim 20 wherein said alkanolamine is ethanolamine or diethanolamine.
Claim 25
Dependent Claim
20 words
The method of claim 18 wherein at least one of said M and M' alkoxides is dissolved in an alcohol.
Claim 26
Dependent Claim
30 words
The method of claim 18 wherein at least one of said M and M' alkoxides is dissolved in an organic amine identical with the amine reacted with said copper alkoxide.
Claim 27
Dependent Claim
12 words
The method of claim 23 wherein said organic amine is ethanol amine.
Claim 28
Dependent Claim
18 words
The method of claim 18 wherein said alkoxides of M, M' and Cu are formed with different alcohols.
Claim 29
Dependent Claim
20 words
The method of claim 25 wherein copper bis methoxide, barium bis ethoxide and yttrium tris isopropoxide are employed as alkoxides.
Claim 30
Dependent Claim
29 words
The method of claim 18 wherein the molar concentrations of said M, M' and Cu alkoxides are selected to provide the stoichiometry M,M' 2 Cu 3 O 6 .5-8.
Claim 31
Dependent Claim
19 words
The method of claim 18 wherein the concentration of said homogenous alkoxide solution is up to about 0.1M alkoxide.
Claim 32
Dependent Claim
137 words
The method of claim 28 wherein said homogenous solution is further manufactured into a ceramic monolith that exhibits superconducting properties when cooled to an appropriate temperature between about 90° K. and about 40° K., said ceramic having the formula M,M' 2 Cu 3 O 6 .5-8 wherein M and M' are as defined in claim 18, comprising: a) hydrolytically decomposing said alkoxides by controlled hydrolysis with a calculated amount of water substantially free of deleterious impurities, thereby forming a solution of the hydroxides of M, M' and Cu; b) forming the solution into a monolith; c) treating the monolith at a temperature of between about 300° C. and about 1100° C. for a period of between about 15 minutes and about 6 hours to remove volatiles and to convert the hydroxides to oxides exhibiting said superconducting properties.
Claim 33
Dependent Claim
79 words
The method of claim 29 wherein step c) is carried out in two steps, comprising: first, calcining the monolith at a temperature of between about 300° C. and about 600° C. for a period of between about 15 and about 60 minutes to remove volatiles and to convert hydroxides to oxides; and second, roasting the monolith at a temperature of between about 800° C. and about 1100° C. for a period of between about 1 and about 5 hours.
Claim 34
Dependent Claim
32 words
The method of claim 30 further comprising the step of adjusting the viscosity of said hydroxide solution obtained in step a) to a value suitable for the preparation of said ceramic monolith.
Claim 35
Dependent Claim
35 words
The method of claim 31 wherein said monolith is a fiber and said hydroxide solution is concentrated to form a sol of the hydroxides prior to carrying out steps b) and c) of claim 29.
Claim 36
Dependent Claim
29 words
The method of claim 30 wherein said monolith is a thin film and said hydroxide solution is diluted prior to carrying out steps b) and c) of claim 29.
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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) | 1995-08-04 | 1996-02-03 | 1996-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-04 | 2000-02-03 | 2000-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-04 | 2004-02-03 | 2004-08-04 | $7700.00 | Window Closed / Lapsed |