US4861753A
Expired / Lapsed
US
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Process for making superconductors using barium nitrate
Assignee: EIDP Inc
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Filing: 1987-06-22
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Granted: 1989-08-29
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Expires: 2007-06-22
Abstract
Abstract There is disclosed an improved process for preparing a superconducting composition having the formula MBa 2 Cu 3 O x wherein M is selected from the group consisiting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; said composition having a superconducting transition temperature of about 90 K.; said process consisiting essentially of mixing ba(NO 3 ) 2 , M 2 O 3 and CuO in an atomic ratio of M:Ba:Cu of about 1:2:3 to form a precursor powder and heating the precursor powder in an oxygen-containing atmoshpere at a temperature from about 875° C. to about 950° C. for a time sufficient to form MBa 2 Cu 3 O y , where y is from about 6.0 to about 6.4; and maintaining the Mba 2 Cu 3 O y in an oxygen-containing atmosphere while cooling for a time sufficient to obtain the desired product.
Inventors
- 👤 Eugene M. McCarron, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:37
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/02; C01F11/04; C01G; C01G3/00; C01G3/006; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4504; C04B35/4508; H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; C01P; C01P2002/00; C01P2002/70; C01P2002/76; Y; Y10; Y10S; Y10S505/00; Y10S505/80; Y10S505/801; Y10S505/809; Y10S505/81; Y10S505/815
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
158 words
An improved process for preparing a superconducting composition having the formula MBa 2 Cu 3 O x wherein M is selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; said process consisting essentially of mixing Ba(NO 3 ) 2 , M 2 O 3 and CuO powders in an atomic ratio of M:Ba:Cu of about 1:2:3 to form a precursor powder and heating the precursor powder in an oxygen-containing atmosphere at a temperature from about 875° C. to about 950° C. for a time sufficient to form MBa 2 Cu 3 O y , where y is from about 6.0 to about 6.4; and maintaining the MBa 2 Cu 3 O y in an oxygen-containing atmosphere while cooling for a time sufficient to obtain the desired product, said process being limited to a single heating step without subsequent grinding and reheating.
Claim 2
Dependent Claim
158 words
An improved process for preparing a superconducting composition having the formula MBa 2 Cu 3 O x wherein M is selected from the group consisting of Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu; x is from about 6.5 to about 7.0; said process consisting essentially of mixing Ba(NO 3 ) 2 , M 2 O 3 and CuO powders in an atomic ratio of M:Ba:Cu of about 1:2:3 to form a precursor powder and heating the precursor powder in an oxygen-containing atmosphere at a temperature from about 875° C. to about 950° C. for a time sufficient to form MBa 2 Cu 3 O y , where y is from about 6.0 to about 6.4; and maintaining the MBa 2 Cu 3 O y in an oxygen-containing atmosphere while cooling for a time sufficient to obtain the desired product, said process being limited to a single heating step without subsequent grinding and reheating.
Claim 3
Dependent Claim
19 words
A process according to claim 1 wherein the precursor powder is pressed into a desired shape prior to heating.
Claim 4
Dependent Claim
23 words
A process according to claim 1 wherein the precursor powder is heated at a temperature from about 900° C. to about 950° C.
Claim 5
Dependent Claim
22 words
A process according to claim 2 wherein the precursor powder is heated at a temperature from about 900° C. to 950° C.
Claim 6
Dependent Claim
15 words
A process according to claim 3 wherein x is from about 6.8 to about 7.0.
Claim 7
Dependent Claim
15 words
A process according to claim 4 wherein x is from about 6.8 to about 7.0.
Claim 8
Dependent Claim
10 words
A process according to claim 5 wherein M is Y.
Claim 9
Dependent Claim
10 words
A process according to claim 6 wherein M is Y.
References Cited (Backward Citations)
JPS5685814A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |