Patent US4962082A successfully refreshed from Google Patents.
US4962082A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making high tc oxide superconductor particles by adjusting pH value and cationic ratio of admixed solution followed by drying, heating and firming
Assignee: Iconectiv LLC
•
Filing: 1987-11-19
•
Granted: 1990-10-09
•
Expires: 2007-11-19
Abstract
Abstract Techniques for the preparation of superconducting perovskites in the MBa 2 Cu 3 O 7-y system wherein M represents yttrium of a rare earth element and y is an integer ranging from 0.1 to 0.8 are described. The techniques involve the use of either a sol-gel or controlled precipitation process in which a barium solution in acetic acid is reacted with copper acetate and either a rare earth hydroxide or rare earth nitrate to form a colloid which is subsequently heated and fired to yield the desired composition. In the embodiment in which the nitrate is employed, the resultant colloid is freeze dried. In both the sol-gel and controlled precipitation processes, heating and firing are required to yield the desired characteristics.
Inventors
- 👤 Philippe Barboux
- 👤 Jean-Marie Tarascon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:10
CPC Classifications
C; C01; C01G; C01G3/00; C01G3/006; C01P; C01P2002/00; C01P2002/30; C01P2002/34; C01P2004/00; C01P2004/60; C01P2004/61; C01P2004/62; Y; Y10; Y10S; Y10S420/00; Y10S420/901; Y10S505/00; Y10S505/725; Y10S505/734; Y10S505/735
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
Method for the preparation of superconducting compositions of the formula MBa 2 Cu 3 O 7 -y wherein M represents yttrium and the rare earth elements and y is an integer ranging from 0.1 to 0.8 which comprises the steps of a. preparing a barium solution in acetic acid, b. adding the solution to a mixture of copper acetate and a rare earth nitrate, c. increasing the pH of the resultant solution to a value at which the rare earth and copper hydroxides are formed, d. forming a viscous gel solution, e. freeze drying the gel to yield a powder which is heated slowly to a temperature of approximately 600° C. to yield a crystalline resistive phase, and f. heating said resistive phase in oxygen at a temperature within the range of 750-950° C. to yield a superconducting single phase perovskite.
Claim 2
Dependent Claim
141 words
Method for the preparation of superconducting compositions of the formula MBa 2 Cu 3 O 7 -y wherein M represents yttrium and the rare earth elements and y is an integer ranging from 0.1 to 0.8 which comprises the steps of a. preparing a barium solution in acetic acid, b. adding the solution to a mixture of copper acetate and a rare earth nitrate, c. increasing the pH of the resultant solution to a value at which the rare earth and copper hydroxides are formed, d. forming a viscous gel solution, e. freeze drying the gel to yield a powder which is heated slowly to a temperature of approximately 600° C. to yield a crystalline resistive phase, and f. heating said resistive phase in oxygen at a temperature within the range of 750-950° C. to yield a superconducting single phase perovskite.
Claim 3
Dependent Claim
14 words
Method in accordance with claim 1 wherein said rare earth nitrate is yttrium nitrate.
Claim 4
Dependent Claim
20 words
Method in accordance with claim 1 wherein the pH of the solution is increased to a value of approximately 6.8.
Claim 5
Dependent Claim
41 words
Method in accordance with claim 1 wherein the freeze drying process is effected over a time period of 24 hours, so resulting in the formation of a hygroscopic, amorphous blue powder having a particle size of the order of 0.5 micron.
Claim 6
Dependent Claim
21 words
Method in accordance with claim 1 wherein said viscous gel is formed by permitting the solution to stand at room temperature.
References Cited (Backward Citations)
US4049789A
Cited
US4567031A
Cited
US4627966A
Cited
US4643984A
Cited
US4588575A
Cited
US4636378A
Cited
US4661282A
Cited
US4676928A
Cited
US4764357A
Cited
US4866031A
Cited
US4804649A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-08 | 1994-04-09 | 1994-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-08 | 1998-04-09 | 1998-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-08 | 2002-04-09 | 2002-10-09 | $7700.00 | Window Closed / Lapsed |