US5045525A
Expired / Lapsed
US
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Method for the synthesis of a high-temperature superconductor of a defined composition
Assignee: Battelle-Institut
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Filing: 1988-05-23
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Granted: 1991-09-03
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Expires: 2008-05-23
Abstract
Abstract A method for the synthesis of an oxide high-temperature superconductor of defined composition by sintering of the starting oxides, wherein sintering is effected in a chemically and phyically closed system by generating a preset oxygen partial pressure through the use of peroxide additives, and the oxidic starting mixture is chemically shielded against the container material and stabilized thermodynamically.
Inventors
- 👤 Helmut Heide
- 👤 Heinrich Winter
- 👤 Eva Poeschel
- 👤 Eckhard Hinze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:23
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; C; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4504; C04B35/4508; C04B35/622; C04B35/64; C04B35/645; C04B35/6455; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/739
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
160 words
A method of producing a substantially stoichiometric, oxidic high-temperature superconductor body from a starting mixture of the general composition SE 1 EA 2 Cu 3 O 7-x , where SE is a rare earth metal or yttrium and EA is an alkaline earth metal, comprising: adding thermally decomposable barium peroxide to the starting mixture to establish a predetermined oxygen partial pressure in the starting mixture; covering the starting mixture containing the barium peroxide with a protective layer whose composition corresponds to that of the respective coexisting phases of the mixture in order to thermodynamically stabilize the desired superconductor phase; enclosing the starting mixture, covered with the protective layer, in a gas-tight container forming a chemically and physically closed system, the protective layer being selected to chemically shield the starting mixture against reaction with the material of the container; and sintering the starting mixture at elevated pressure while the starting mixture, covered with the protective layer, is enclosed in the container.
Claim 2
Independent Claim
160 words
A method of producing a substantially stoichiometric, oxidic high-temperature superconductor body from a starting mixture of the general composition SE 1 EA 2 Cu 3 O 7-x , where SE is a rare earth metal or yttrium and EA is an alkaline earth metal, comprising: adding thermally decomposable barium peroxide to the starting mixture to establish a predetermined oxygen partial pressure in the starting mixture; covering the starting mixture containing the barium peroxide with a protective layer whose composition corresponds to that of the respective coexisting phases of the mixture in order to thermodynamically stabilize the desired superconductor phase; enclosing the starting mixture, covered with the protective layer, in a gas-tight container forming a chemically and physically closed system, the protective layer being selected to chemically shield the starting mixture against reaction with the material of the container; and sintering the starting mixture at elevated pressure while the starting mixture, covered with the protective layer, is enclosed in the container.
Claim 3
Dependent Claim
36 words
A method according to claim 1, wherein said protective layer is surrounded by a second layer of inert material to further chemically shield the superconductor and protective layer against reaction with the material of the container.
Claim 4
Dependent Claim
13 words
A method according to claim 2, wherein said inert material is boron nitride.
Claim 5
Dependent Claim
23 words
A method as defined in claim 1 wherein the starting mixture comprises Y 1 Ba 2 Cu 3 O 7-X of perovskite structure.
Claim 6
Dependent Claim
55 words
A method as defined in claim 1 further comprising, after said step of covering and before said step of enclosing, compacting the covered starting mixture by performing cold isostatic pressing, and wherein said step of sintering includes a high-pressure synthesis at gas pressures of 500 to 4000 bar and temperatures between 300° and 1200° C.
Claim 7
Dependent Claim
25 words
A method as defined in claim 5, wherein said step of sintering further comprises, after the high pressure synthesis, cooling the superconductor body under pressure.
Claim 8
Dependent Claim
50 words
A method as defined in claim 1 wherein said step of sintering includes a high pressure synthesis explosive compacting procedure carried out by embedding the starting mixture, covered with the protective layer and enclosed in the container, in an explosive and in a pressure-proof explosion chamber, and igniting the explosive.
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) | 1994-09-02 | 1995-03-04 | 1995-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-02 | 1999-03-04 | 1999-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-02 | 2003-03-04 | 2003-09-03 | $7700.00 | Window Closed / Lapsed |