# US 5,346,883 A · Method of manufacturing superconductive products > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,346,883 A - Document ID: US5346883A - Status: Granted - Kind: A - Application number: 08/009,383 - Filed: 1993-01-27 - Granted: 1994-09-13 - Earliest claimed: 1987-08-21 - Assignees: Furukawa Electric Co., Ltd. - Inventors: Shoji Shiga; Naoki Uno; Yasuzo Tanaka - Web page: https://patentgrep.com/patent/US5346883A ## CPC - C30B 29/225: {based on rare earth copper oxides, e.g. high T-superconductors} - C04B 35/45: based on copper oxide or solid solutions thereof with other oxides - C04B 35/4508: {Type 1-2-3} - C04B 35/4521: {containing bismuth oxide} - C04B 35/653: Processes involving a melting step - C30B 11/00: Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method (C30B13/00, C30B15/00, C30B17/00, C30B19/00 take precedence; under a protective fluid C30B27/00) - H10N 60/0801: {Manufacture or treatment of filaments or composite wires} - H10N 60/203: {comprising high-Tc ceramic materials} - Y10S 505/704: Wire, fiber, or cable - Y10S 505/74: To form wire or fiber - Y10T 29/49014: Superconductor - C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention provides a method of manufacturing superconductive products comprising heating a superconductive matter or incorporation including its precursor to a temperature higher than its or its precursor's melting point to melt it or its precursor, and then solidifying and cooling it in a direction in such a way that it is re-crystalized to have an orientation in the longitudinal direction of its incorporation. ## Claims ### Claim 1 A method of manufacturing a superconductive product comprising: heating a longitudinally elongated body comprising a superconductive material selected from the group consisting of BiSrCaCu.sub.2 O.sub.y and Tl.sub.2 Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.z to a temperature higher than the melting point of the superconductive material, thereby melting the superconductive material and obtaining a molten superconductive material; and continuously passing said elongated body through a furnace having a temperature gradient from a high temperature region in the furnace toward a low temperature region in an outlet of the furnace, the temperature gradient being 100.degree. C./cm, wherein the temperature in the outlet of the furnace is lower then the melting point of the superconductive material, so as to cool the molten superconductive material in the longitudinal direction of said elongated body, wherein an average cooling rate for cooling the molten superconductive material is 1.degree. C./minute, thereby solidifying and recrystallizing the superconductive material along said elongated body such that the a-axis or the b-axis of each crystal of the superconductive material is oriented in the longitudinal direction of said elongated body. ### Claim 2 (depends on 1) The method according to claim 1, wherein said elongated body is prepared by filling the superconductive material into a line-like metal pipe. ### Claim 3 (depends on 1) The method according to claim 1, wherein said elongated body is prepared by filling the superconductive material into a plurality of line-like metal pipes. ### Claim 4 (depends on 1) The method according to claim 1, wherein the superconductive material is an oxide superconductor. ### Claim 5 (depends on 1) The method according to claim 1, wherein the heating and cooling are carried out in an oxygen-rich atmosphere. ### Claim 6 (depends on 1) The method according to claim 1, wherein a small amount of metal peroxide is mixed in advance with the superconductive material. ### Claim 7 (depends on 6) The method according to claim 6, wherein the metal peroxide is silver peroxide. ### Claim 8 (depends on 1) The method according to claim 1, wherein the temperature in the outlet of the furnace is about 500.degree. C. ### Claim 9 (depends on 1) The method according to claim 1, wherein the superconductive material is BiSrCaCu.sub.2 O.sub.y. ### Claim 10 (depends on 1) The method according to claim 1, wherein the superconductive material is Tl.sub.2 Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.z. ### Claim 11 A method of manufacturing a superconductive product comprising: heating a longitudinally elongated body comprising a precursor of a superconductive material selected from the group consisting of BiSrCaCu.sub.2 O.sub.y and Tl.sub.2 Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.z to a temperature higher than the melting point of said precursor, thereby melting said precursor and obtaining a molten precursor; and then continuously passing said elongated body through a furnace having a temperature gradient from a high temperature region in the furnace toward a low temperature region in an outlet of the furnace, the temperature gradient being 100.degree. C./cm, wherein the temperature in the outlet of the furnace is lower then the melting point of the superconductive material, so as to cool the molten superconductive material in the longitudinal direction of said elongated body, wherein an average cooling rate for cooling the molten superconductive material is 1.degree. C./minute, thereby converting said precursor into a superconductive material and solidifying and recrystallizing the superconductive material along said elongated body such that the a-axis or the b-axis of each crystal of the superconductive material is oriented in the longitudinal direction of said elongated body. ### Claim 12 (depends on 11) The method according to claim 11, wherein said elongated body is prepared by filling the precursor into a line-like metal pipe. ### Claim 13 (depends on 11) The method according to claim 11, wherein said elongated body is prepared by filling the precursor into a plurality of line-like metal pipes. ### Claim 14 (depends on 11) The method according to claim 11, wherein said precursor of the superconductive material is made of a material selected from the group consisting of an oxide, a hydroxide, a halide, a carbonate and a nitrate of an inorganic acid, an acetate, an oxalate or an alkoxide, which all include a constituent element of an oxide superconductor including at least an alkaline earth metal and copper. ### Claim 15 (depends on 11) The method according to claim 11, wherein said heating and cooling are carried out in an oxygen-rich atmosphere. ### Claim 16 (depends on 11) The method according to claim 11, wherein a small amount of metal peroxide is previously mixed with said precursor. ### Claim 17 (depends on 16) The method according to claim 16, wherein the metal peroxide is silver peroxide. ### Claim 18 (depends on 11) The method according to claim 11, wherein the temperature in the outlet of the furnace is about 500.degree. C. ### Claim 19 (depends on 11) The method according to claim 11, wherein the superconductive material is BiSrCaCu.sub.2 O.sub.y. ### Claim 20 (depends on 11) The method according to claim 11, wherein the superconductive material is Tl.sub.2 Ba.sub.2 Ca.sub.2 Cu.sub.3 O.sub.z.