Patent US4937225A successfully refreshed from Google Patents.
US4937225A
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Rapid solidification processing of oxide superconductors
Assignee: Massachusetts Institute of Technology
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Filing: 1987-07-10
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Granted: 1990-06-26
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Expires: 2007-07-10
Abstract
Abstract A superconducting oxide is melted in an oxygen-rich environment, rapidly solidified and annealed in an oxygen atmosphere. The resulting material has a fine grain structure, is chemically homogeneous, and has enhanced resistance to environmental degradation. The materials have well-defined superconducting characteristics as measured through the temperature dependence of their resistivities and diamagnetic susceptibilities.
Inventors
- 👤 Gretchen Kalonji
- 👤 Joanna McKittrick
- 👤 Shinichi Sasayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:24
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4504; C04B35/622; C04B35/653; H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/73; Y10S505/733
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
37 words
Method for processing a copper-containing superconducting oxide comprising: melting the oxide in an oxygen-rich environment; rapidly solidifying the oxide at a rate greater than 10 3 K per second; and annealing the oxide in an oxygen-rich atmosphere.
Claim 2
Dependent Claim
37 words
Method for processing a copper-containing superconducting oxide comprising: melting the oxide in an oxygen-rich environment; rapidly solidifying the oxide at a rate greater than 10 3 K per second; and annealing the oxide in an oxygen-rich atmosphere.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein the oxide is melted with an O 2 --H 2 torch having an oxygen rich flame.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein the superconducting oxide before melting is a sintered pellet.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein the solidification rate is in the range of 10 5 -10 6 K per second.
Claim 6
Dependent Claim
12 words
The method of claim 1 wherein the rapid solidification comprises gas atomization.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein the rapid solidification comprises twin-rolling quenching.
Claim 8
Dependent Claim
18 words
The method of claim 1 wherein the rapid solidification comprises contacting the melting oxide with a spinning wheel.
Claim 9
Dependent Claim
11 words
The method of claim 7 wherein the spinning wheel is copper.
Claim 10
Dependent Claim
16 words
The method of claim 7 wherein the spinning wheel rotates in the range of 2,000-5,000 rpm.
Claim 11
Dependent Claim
16 words
The method of claim 6 wherein the twin rollers rotate in the range of 2,000-6,000 rpm.
Claim 12
Dependent Claim
17 words
The method of claim 1 wherein the superconducting oxide is YBa 2 Cu 3 O 7-x .
Claim 13
Dependent Claim
23 words
The method of claim 1 wherein the superconducting oxide includes metallic elements selected from the group Y, La, Ba, Cu, Sr, Eu, Lu.
Claim 14
Dependent Claim
14 words
The method of claim 1 wherein the superconducting oxide comprises Y, Ba, and Cu.
Claim 15
Dependent Claim
14 words
A superconducting oxide prepared according to the method of one of claims 1-3, 4-13.
Claim 16
Dependent Claim
12 words
A superconducting oxide prepared according to claim 1 having a crystalline structure.
Claim 17
Dependent Claim
14 words
A superconductive oxide prepared according to claim 1 having an amorphous or glassy structure.
Claim 18
Dependent Claim
13 words
A superconducting oxide prepared according to claim 15 wherein the structure is cubic.
Claim 19
Dependent Claim
13 words
A superconducting oxide prepared according to claim 15 wherein the structure is orthorhombic.
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) | 1993-06-25 | 1993-12-25 | 1994-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-25 | 1997-12-25 | 1998-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-25 | 2001-12-25 | 2002-06-26 | $7700.00 | Window Closed / Lapsed |