US5064808A
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Method of manufacturing oxide superconductors using self-propagating high-temperature synthesis
Assignee: INSTITUT STRUKTURNOI
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Filing: 1988-05-20
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Granted: 1991-11-12
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Expires: 2008-05-20
Abstract
Abstract PCT No. PCT/SU88/00113 Sec. 371 Date Nov. 22, 1989 Sec. 102(e) Date Nov. 22, 1989 PCT Filed May 20, 1988 PCT Pub. No. WO88/09311 PCT Pub. Date Dec. 1, 1988.The invention relates to production of superconductors, more particularly, LnM2IIM3IOy compounds where y=6-8; Ln=Y, Sc or lanthanide; MII=Ba, Ca or Sr; MI=Cu, Cu+Ag or LnM2IIMIOy-xF where x=1-2. It comprises local initiation of an exothermic reaction in a stoichiometric mixutre of source constituents chosen to provide for production of the afore-mentioned compounds. An exothermic mixture of corresponding constituents includes a non-combustible component and a combustible component comprising at least one metal from the group composed of a rare-earth metal of the periodic system chosen from scandium, yttrium and lanthanide, a metal of group II of the periodic system, a metal of group I of the periodic system or hydride of at least one of said metals.
Inventors
- 👤 Alexandr G. Merzhanov
- 👤 Inna P. Borovinskaya
- 👤 Mikael D. Nersesian
- 👤 Andrei G. Peresada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:14
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4504; C04B35/4508; C04B35/622; C04B35/64; C04B35/65; C04B35/651; H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/80; H10N60/85; H10N60/855; H10N60/857; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/737
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
219 words
A process for producing a superconducting oxide material, the process comprising: providing an exothermic mixture of stoichiometric starting amounts of non-combustible and combustible components, the non-combustible component being a mixture of at least one oxide, halide, nitrate, carbonate or oxalate of at least one rare earth metal selected from the group consisting of scandium, yttrium, and lanthanides; at least one oxide, peroxide, carbonate, nitrate or halide of a metal selected from the group consisting of copper, silver and gold; and at least one oxide, peroxide, carbonate, nitrate or halide of a metal selected from the group consisting of calcium, strontium, barium and radium, and the combustible component being selected from the group consisting of at least one of the rare earth metal; a metal selected from the group consisting of copper, silver and gold; a metal selected from the group consisting of calcium, strontium, barium, and radium; a hydride of the rare earth metal, and a hydride of the metal of the group of calcium, strontium, barium and radium; placing the exothermic mixture in an oxygen-containing medium having a stoichiometric excess of an oxidizing agent; locally igniting the exothermic mixture at any point thereof for initiating a reaction thereof; and maintaining the excess of the oxidizing agent until the reaction is completed, whereby to provide a superconducting oxide material.
Claim 2
Dependent Claim
219 words
A process for producing a superconducting oxide material, the process comprising: providing an exothermic mixture of stoichiometric starting amounts of non-combustible and combustible components, the non-combustible component being a mixture of at least one oxide, halide, nitrate, carbonate or oxalate of at least one rare earth metal selected from the group consisting of scandium, yttrium, and lanthanides; at least one oxide, peroxide, carbonate, nitrate or halide of a metal selected from the group consisting of copper, silver and gold; and at least one oxide, peroxide, carbonate, nitrate or halide of a metal selected from the group consisting of calcium, strontium, barium and radium, and the combustible component being selected from the group consisting of at least one of the rare earth metal; a metal selected from the group consisting of copper, silver and gold; a metal selected from the group consisting of calcium, strontium, barium, and radium; a hydride of the rare earth metal, and a hydride of the metal of the group of calcium, strontium, barium and radium; placing the exothermic mixture in an oxygen-containing medium having a stoichiometric excess of an oxidizing agent; locally igniting the exothermic mixture at any point thereof for initiating a reaction thereof; and maintaining the excess of the oxidizing agent until the reaction is completed, whereby to provide a superconducting oxide material.
Claim 3
Dependent Claim
62 words
The process according to claim 1, wherein the ratio between the starting amounts of the combustible and non-combustible components is selected such that the stoichiometric ratio of the rare earth metal: metal of the group consisting of copper, silver and gold: metal of the group consisting of calcium, strontium, barium and radium: oxidizing agent in the superconducting oxide materials is 1:2:3: (6-8).
Claim 4
Dependent Claim
31 words
The process according to claim 1, wherein the exothermal mixture has the following proportions of the components in percent by mass: ______________________________________
combustible 6.55 to 39.46
non-combustible
60.54 to 93.45.
______________________________________
Claim 5
Dependent Claim
21 words
The process according to claim 1, wherein the non-combustible component comprises at least one halide or nitrate of the metals thereof.
Claim 6
Dependent Claim
18 words
The process according to claim 1, wherein the non-combustible component comprises the halide and the halide is fluoride.
Claim 7
Dependent Claim
29 words
The process according to claim 1, wherein the metal of at least one of the groups consisting of copper, silver and gold is copper, silver or a mixture thereof.
Claim 8
Dependent Claim
34 words
The process according to claim 1, wherein the metal of at least one of the groups consisting of calcium, strontium, barium and radium is selected from the group consisting of calcium, strontium and barium.
Claim 9
Dependent Claim
23 words
A process according to claim 1, wherein the reaction is carried out at a pressure of from about 0.1 to about 15 MPa.
Claim 10
Dependent Claim
16 words
The process according to claim 8, wherein the reaction is carried out at about 0.1 MPa.
Claim 11
Dependent Claim
23 words
A process according to claim 7, characterized in that the metal of the group consisting of calcium, strontium, barium and radium is barium.
Claim 12
Dependent Claim
33 words
A process according to claim 1, characterized in that the combustible component is a mixture of the rare-earth metal with at least one metal of the group consisting of copper, silver and gold.
Claim 13
Dependent Claim
40 words
A process according to claim 1, characterized in that the combustible component is a mixture of the metal of the group consisting of copper, silver and gold and the metal of the group consisting of calcium, strontium, barium and radium.
Claim 14
Dependent Claim
35 words
A process according to claim 1, characterized in that the combustible component comprises the hydride of the rare-earth metal and the hydride of the metal of the group consisting of calcium, strontium, barium and radium.
Claim 15
Dependent Claim
25 words
A process according to claim 13, characterized in that the combustible component comprises the metal of the group consisting of calcium, strontium, barium and radium.
Claim 16
Dependent Claim
26 words
A process according to claim 1, characterized in that the non-combustible component comprises the halide or the nitrate of at least one of the metals thereof.
Claim 17
Dependent Claim
22 words
A process according to claim 15, wherein the non-combustible component comprises the halide and the halide is a fluoride, bromide or chloride.
Claim 18
Dependent Claim
13 words
A process according to claim 16, characterized in that the halide is fluoride.
Claim 19
Dependent Claim
17 words
A process according to claim 17, characterized in that the fluoride is of copper, silver or gold.
Claim 20
Dependent Claim
43 words
A process according to claim 1, characterized in that the oxygen-containing medium is oxygen, or a mixture of oxygen (20-95% by volume) with at least one additive of the series: argon, nitrogen, air, fluorine, in an amount of 5 to 80% by volume.
Claim 21
Dependent Claim
23 words
A process according to claim 19, characterized in that the oxygen-containing medium is oxygen or a mixture thereof with air, argon or fluorine.
Claim 22
Dependent Claim
19 words
A process according to claim 1, characterized in that combustion of the exothermal mixture is conducted under atmospheric pressure.
Claim 23
Dependent Claim
24 words
A process according to claim 1, characterized in that combustion of the exothermal mixture is conducted under a pressure of 0.2 to 15 MPa.
Claim 24
Dependent Claim
29 words
A process according to claim 1, characterized in that the starting components of the exothermal mixture are preliminarily disintegrated to a particle size of from 0.01 to 0.1 mm.
Claim 25
Dependent Claim
24 words
A process according to claim 4, characterized in that thermal mixture of the components prior to initiation of combustion is heated to 100°-600° C.
Claim 26
Dependent Claim
52 words
A process according to claim 1, characterized in that the local ignition of the exothermal mixture is effected by means of an electric filament, electric arc, electric spark, or by means of a light or laser beam, or by means of an electron beam, or by means of a high-frequency induction heating.
Claim 27
Dependent Claim
25 words
A process according to claim 25, characterized in that the local ignition of the exothermal mixture is effected predominantly by means of an electric filament.
Claim 28
Dependent Claim
22 words
A process according to claim 1, characterized in that the exothermal mixture of the components is preliminarily moulded as a predetermined-shape article.
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