EP0290357A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for the preparation of copper oxide ceramic superconductive articles, and process for their preparation
Assignee: Eastman Kodak Co
•
Filing: 1988-05-02
•
Granted: —
•
Expires: 2008-05-02
Abstract
Abstract Articles are disclosed in which an electrically conductive layer on a substrate exhibits a superconducting transition temperature in excess of 30°K. Conductive layers are disclosed comprised of a crystalline rare earth alkaline earth copper oxide. Processes of preparing these articles are disclosed in which a mixed metal oxide precursor composition is coated and heated to its thermal decomposition temperature to create an amorphous mixed metal oxide layer. The amorphous layer is then heated to its crystallization temperature.
Inventors
- 👤 Jose Manuel Mir
- 👤 John Alphonse Agostinelli
- 👤 David Lynn Peterson
- 👤 Gustavo Roberto Paz-Pujalt
- 👤 Brian James Highberg
- 👤 Gopalan Rajeswaran
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 20:20
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C03; C03C; C03C17/00; C03C17/22; C03C17/23; C04B35/00; C04B35/01; C04B35/45; C04B35/4504; C04B41/45; C04B41/50; C04B41/5025; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C23; C23C; C23C26/00; H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0296; H10N60/0324; H10N60/0801; C03C2217/00; C03C2217/20; C03C2217/21; C03C2217/23; C04B2111/00; C04B2111/00474; C04B2111/00844
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
33 words
An article comprised of a substrate and an electrically conductive layer located on the substrate characterized in that the electrically conductive layer is comprised of a crystalline rare earth alkaline earth copper oxide.
Claim 2
Dependent Claim
33 words
An article comprised of a substrate and an electrically conductive layer located on the substrate characterized in that the electrically conductive layer is comprised of a crystalline rare earth alkaline earth copper oxide.
Claim 3
Dependent Claim
29 words
An article according to claim 1 further characterized in that the conductive layer is restricted to a portion of the substrate thereby defining a conduction path on the substrate.
Claim 4
Dependent Claim
28 words
An article according to claim 1 further characterized in that the substrate is of an elongated configuration and the conductive layer forms a conductive sheath surrounding the substrate.
Claim 5
Dependent Claim
19 words
An article according to claim 3 further characterized in that both the substrate and the conductive layer are flexible.
Claim 6
Dependent Claim
21 words
An article according to claim 4 further characterized in that the conductive layer has a thickness of 2 µm or less.
Claim 7
Dependent Claim
18 words
An article according to claim 1 or 2 further characterized in that the substrate is comprised of glass.
Claim 8
Dependent Claim
22 words
An article according to any one of claims 1 to 5 inclusive further characterized in that the substrate is comprised of metal.
Claim 9
Dependent Claim
27 words
An article according to claim 7 further characterized in that at least the surface of the substrate contacting the conductive layer is comprised of a refractory metal.
Claim 10
Dependent Claim
20 words
An article according to claim 1 or 2 further characterized in that the substrate is comprised of a metal oxide.
Claim 11
Dependent Claim
21 words
An article according to claim 9 further characterized in that the substrate is comprised of alumina or an alkaline earth oxide.
Claim 12
Dependent Claim
16 words
An article according to claim 10 further characterized in that the substrate is comprised of magnesia.
Claim 13
Dependent Claim
16 words
An article according to claim 10 further characterized in the substrate is comprised of strontium titanate.
Claim 14
Dependent Claim
19 words
An article according to claim 1 or 2 further characterized in that the substrate is in a monocrystalline form.
Claim 15
Dependent Claim
17 words
An article according to claim 13 further characterized in that the substrate exhibits a perovskite crystal structure.
Claim 16
Dependent Claim
18 words
An article according to claim 13 further characterized in that the substrate exhibits a tetragonal K₂NiF₄ crystal structure.
Claim 17
Dependent Claim
22 words
An article according to claim 1 further characterized in that a barrier is interposed between the substrate and the electrically conductive layer.
Claim 18
Dependent Claim
28 words
An article according to any one of claims 1 to 16 inclusive further characterized in that the conductive layer exhibits a superconducting transition temperature of at least 30°K.
Claim 19
Dependent Claim
22 words
An article according to claim 17 further characterized in that the conductive layer exhibits a superconducting transition temperature of at least 80°K.
Claim 20
Dependent Claim
26 words
An article according to claim 17 further characterized in that the conductive layer consists of greater than 45 percent by volume of a crystalline conductive phase.
Claim 21
Dependent Claim
26 words
An article according to claim 19 further characterized in that the conductive layer consists of greater than 70 percent by volume of a crystalline conductive phase.
Claim 22
Dependent Claim
26 words
An article according to claim 20 further characterized in that the conductive layer consists of greater than 90 percent by volume of a crystalline conductive phase.
Claim 23
Dependent Claim
47 words
An article according to any one of claims 1 to 21 inclusive further characterized in that the rare earth alkaline earth copper oxide satisfies the metal ratio: L 2-x :M x :Cu where L is lanthanide, M is alkaline earth metal, and x is 0.05 to 0.30.
Claim 24
Dependent Claim
23 words
An article according to claim 22 further characterized in that the lanthanide is lanthanum and the alkaline earth metal is barium or strontium.
Claim 25
Dependent Claim
17 words
An article according to claim 22 or 23 further characterized in that x is 0.15 to 0.20.
Claim 26
Dependent Claim
43 words
An article according to any one of claims 1 to 21 inclusive further characterized in that greater than 45 percent by volume of the conductive layer consists essentially of a rare earth alkaline earth copper oxide which is in an R₁A₂C₃ crystalline phase.
Claim 27
Dependent Claim
41 words
An article according to claim 25 further characterized in that the rare earth alkaline earth copper oxide consists of yttrium as the rare earth and barium, optionally in combination with at least one of strontium and calcium, as the alkaline earth.
Claim 28
Dependent Claim
31 words
An article according to claim 26 further characterized in that the metals present in the R₁A₂C₃ crystalline phase consist essentially of yttrium, alkaline earth, and copper in a 1:2:3 mole ratio.
Claim 29
Dependent Claim
36 words
An article according to claim 25 to 27 further characterized in that the conductive layer contains at least one additional phase comprised of an oxide of at least one of rare earth, alkaline earth, and copper.
Claim 30
Dependent Claim
27 words
An article according to any one of claims 1 to 28 inclusive further characterized in that the conductive layer exhibits superconductivity at temperature in excess of 10°K
Claim 31
Dependent Claim
22 words
A superconductive article according to claim 29 further characterized in that the conductive layer exhibits superconductivity at temperatures in excess of 30°K.
Claim 32
Dependent Claim
85 words
A process comprising applying to a substrate metal oxide precursors and thermally decomposing the precursors, characterized in that onto the substrate is coated a solution consisting essentially of a volatilizable film forming solvent and metal-ligand compounds of each of rare earth, alkaline earth, and copper containing at least one thermally volatilizable ligand and the solvent and ligands are removed from the substrate, this step including heating in the presence of oxygen to form an amorphous rare earth alkaline earth copper oxide coating on the substrate.
Claim 33
Dependent Claim
85 words
A process comprising applying to a substrate metal oxide precursors and thermally decomposing the precursors, characterized in that onto the substrate is coated a solution consisting essentially of a volatilizable film forming solvent and metal-ligand compounds of each of rare earth, alkaline earth, and copper containing at least one thermally volatilizable ligand and the solvent and ligands are removed from the substrate, this step including heating in the presence of oxygen to form an amorphous rare earth alkaline earth copper oxide coating on the substrate.
Claim 34
Dependent Claim
43 words
A process according to claim 31 further characterized in that the amorphous rare earth alkaline earth copper oxide is converted to a crystalline coating by heating the amorphous coating to a temperature at which rare earth alkaline earth copper oxide crystals are formed.
Claim 35
Dependent Claim
24 words
A process according to claim 32 further characterized in that the amorphous oxide is heated to its crystallization temperature by exposure to electromagnetic radiation.
Claim 36
Dependent Claim
19 words
A process according to claim 33 further characterized in that the electromagnetic radiation is absorbed by the amorphous coating.
Claim 37
Dependent Claim
23 words
A process according to claim 33 or 34 further characterized in that the substrate is chosen to be transmissive to the electromagnetic radiation.
Claim 38
Dependent Claim
27 words
A process according to any one of claims 33 to 35 inclusive further characterized in that the electromagnetic radiation is coherent monochromatic radiation supplied from a laser.
Claim 39
Dependent Claim
22 words
A process according to claim 36 further characterized in that the laser is employed to form a crystalline pattern on the substrate.
Claim 40
Dependent Claim
51 words
A process according to claim 32 further characterized in the the amorphous coating is converted to a crystalline coating by heating the amorphous coating to a temperature at which nucleation of rare earth alkaline earth copper oxide crystals is achieved and then growing these crystals to larger sizes by further heating.
Claim 41
Dependent Claim
22 words
A process according to claim 38 further characterized in that the crystals are grown at a higher temperature than their nucleation temperature.
Claim 42
Dependent Claim
29 words
A process according to any one of claims 32, 38, or 39 further characterized in that the coating and solvent and ligand removal steps are repeated prior to crystallization.
Claim 43
Dependent Claim
24 words
A process according to any one of claims 38 to 40 further characterized in that the crystalline coating is annealed to improve crystalline order.
Claim 44
Dependent Claim
28 words
A process according to claim 41 further characterized in that the crystalline coating is cooled at a rate of 25°C per minute or less to improve crystalline order.
Claim 45
Dependent Claim
22 words
A process according to claim 41 or 42 further characterized in that the crystalline coating is enriched with oxygen following crystal growth.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.