US4870052A
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Tl-Ca-Ba-Cu-O compositions electrically superconducting above 120 degree K and processes for their preparation
Assignee: International Business Machines Corp
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Filing: 1988-03-08
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Granted: 1989-09-26
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Expires: 2008-03-08
Abstract
Abstract Stable, bulk electrical superconductors are prepared by heating mixed metal oxides in the presence of oxygen in a closed vessel in a preheated oven for 1-5 hours at 850°-900° C. The final oxides are in the molar ratio Tol 0 .6-1.1 Ca 2-3 Ba 0 .75-1.25 Cu 2-3 O.sub.(5+δ)-(9+δ), where δ is less than one.
Inventors
- 👤 Edward M. Engler
- 👤 Victor Y. Lee
- 👤 Adel I. Nazzal
- 👤 Stuart S. P. Parkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:06
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4512; H; H10; H10N; H10N60/00; H10N60/80; H10N60/85; H10N60/855; H10N60/857
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
39 words
A stable, bulk electrical superconductor with zero resistance above 120° K. confirmed with magnetic susceptibility measurements, having a composition in the range Tl 0 .6-1.1 Ca 2-3 Ba 0 .75-1.25 Cu 2-3 O.sub.(5+δ)-(9+δ), where δ is less than one.
Claim 2
Dependent Claim
39 words
A stable, bulk electrical superconductor with zero resistance above 120° K. confirmed with magnetic susceptibility measurements, having a composition in the range Tl 0 .6-1.1 Ca 2-3 Ba 0 .75-1.25 Cu 2-3 O.sub.(5+δ)-(9+δ), where δ is less than one.
Claim 3
Dependent Claim
27 words
A composition as claimed in claim 1 wherein the material is Tl 0 .8 Ca 3 Ba 1 Cu 8+ δ, where δ is less than one.
Claim 4
Dependent Claim
29 words
A composition as claimed in claim 1 wherein the material is Tl 0 .8 Ca 2 Ba 1 Cu 3 O 7+ δ where δ is less than one.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |