Oxide superconductor and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-11501899-B2
Application number	US-202117140013-A
Country	US
Kind code	B2
Filing date	Jan 1, 2021
Priority date	Feb 26, 2016
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

An oxide superconductor according to an embodiment includes an oxide superconducting layer includes a single crystal having a continuous perovskite structure containing at least one rare earth element selected from the group consisting of yttrium, lanthanum, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium, barium, and copper, containing praseodymium in a part of the site of the rare earth element in the perovskite structure, and having a molar ratio of praseodymium of 0.00000001 or more and 0.2 or less with respect to the sum of the at least one rare earth element and praseodymium; fluorine in an amount of 2.0×10 15 atoms/cc or more and 5.0×10 19 atoms/cc or less; and carbon in an amount of 1.0×10 17 atoms/cc or more and 5.0×10 20 atoms/cc or less.

First claim

What is claimed is:

1. A method for manufacturing an oxide superconductor, comprising:
preparing an aqueous solution containing an acetate of at least one rare earth element selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), an acetate of praseodymium (Pr), an acetate of barium (Ba), and an acetate of copper (Cu), and the aqueous solution having a molar ratio of praseodymium of 0.00000001 or more and 0.2 or less with respect to the sum of the at least one rare earth element and praseodymium;
mixing the aqueous solution with a perfluorocarboxylic acid to prepare a mixed solution;
subjecting the mixed solution to a reaction and purification to prepare a first gel;
adding an alcohol containing methanol to the first gel and dissolving the first gel therein to prepare an alcohol solution;
subjecting the alcohol solution to a reaction and purification to prepare a second gel;
adding an alcohol containing methanol to the second gel and dissolving the second gel therein to prepare a coating solution in which a total weight of residual water and residual acetic acid is 2 wt % or less;
applying the coating solution onto a substrate to form a gel film;
subjecting the gel film to calcining at 400° C. or lower to form a calcined film; and
subjecting the calcined film to firing under a humidified atmosphere at 725° C. or higher and 850° C. or lower and oxygen annealing to form an oxide superconducting layer.

2. The method for manufacturing an oxide superconductor according to claim 1 , wherein the oxide superconducting layer has perovskite structure.

3. The method for manufacturing an oxide superconductor according to claim 1 , wherein 98 mol % or more of the perfluorocarboxylic acid is trifluoroacetic acid.

Assignees

• Toshiba Kk

Inventors

• Hayashi Mariko
• Araki Takeshi
• Fuke Hiroyuki
• Kobayashi Nao

Classifications

• C04B35/62218

  obtaining ceramic films, e.g. by using temporary supports · CPC title

• C01P2002/34

  perovskite-type (ABO3) · CPC title

• H01B12/16

  characterised by cooling · CPC title

• H01B12/06 Primary

  Films or wires on bases or cores · CPC title

• C04B2235/768

  Perovskite structure ABO3 · CPC title