Oxide superconductor and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-2017309805-A1
Application number	US-201715646752-A
Country	US
Kind code	A1
Filing date	Jul 11, 2017
Priority date	Sep 16, 2015
Publication date	Oct 26, 2017
Grant date	—

Abstract

An oxide superconductor includes: REBa 2 Cu 3 O 7-x (RE being one element selected from a “RE element group” of Pr, Nd, Sm, Eu, Gd, Y, Tb, Dy, Ho, Er, Tm, Yb, and Lu). The RE includes at least three, types of metallic elements (M1, M2, and M3), and the three types of metallic elements are any element of the RE element group selected in order. In an oxide system satisfying R(1)≦20 mol % and R(M2)≧60 mol % and R(M3)≦20 mol %, R(M1) being an average metallic element ratio of M1 in M1+M2+M3, SD(Ms)>0.15 is satisfied at a position at 50% of an average film thickness of a cross section including the c-axis, Ms being the metallic element of not larger of R(M1) and R(M3), SD(Ms) being a standard deviation/average value of a concentration of Ms.

First claim

What is claimed is:

1 . An oxide superconductor, comprising;
REBa 2 Cu 3 O 7-x (RE being one element selected from a “RE element group” of Pr, Nd, Sm, Eu, Gd, Y, Tb, Dy, Ho, Er, Tm, Yb, and Lu) including fluorine and carbon, the fluorine having a concentration of not less than 2.0×10 16 atoms/cc and not more than 5.0×10 19 atoms/cc, the carbon having a concentration of not less than 1.0×10 18 atoms/cc and not more than 5.0×10 20 atoms/cc, RE including at least three types of metallic elements (M1, M2, and M3), the three types of metallic elements being any element of the RE element group selected in order, R(M1)≦20 mol % and R(M2)≧60 mol % and R(M3)≦20 mol % being satisfied, R(M1) being an average metallic element ratio of M1 in M1+M2+M3, the REBa 2 Cu 3 O 7-x having a single perovskite structure oriented in a c-axis, SD(Ms)>0.15 being satisfied at a position at 50% of an average film thickness of a cross section including the c-axis, Ms being the metallic element of not larger of R(M1) or R(M3), SID(Ms) being a standard deviation of concentration values of Ms over the average value of the Ms concentration.

2 . The oxide superconductor according to claim 1 , wherein the SD(Ms)>0.25 is satisfied.

3 . The oxide superconductor according to claim 1 , wherein the oxide layer is provided on a base member, or the oxide layer is provided on an intermediate layer provided on the base member.

4 . The oxide superconductor according to claim 1 , wherein the M1 is Pr, Nd, or Sm. cm 5 . An oxide superconductor, comprising:
REBa 2 Cu 3 O 7-x (RE being one element selected from, a “RE element group” of Pr, Nd, Sm, Eu, Gd, Y, Tb, Dy, Flo, Er, Tm, Yb, and Lu) including fluorine and carbon, the fluorine having a concentration of not less than 2.0×10 16 atoms/cc and not more than 5.0×10 19 atoms/cc, the carbon having a concentration of not less than 1.0×10 18 atoms/cc and not more than 5.0×10 20 atoms/cc, RE including at least three types of metallic elements (M1, M2, and M3), the three types of metallic elements being any element of the RE element group selected in order, R(M1)≦20 mol % and R(M2)≧60 mol % and R(M3)≦20 mol % being satisfied, R(M1) being an average metallic element ratio of M1 in M1+M2+M3, the REBa 2 Cu 3 O 7-x having a single perovskite structure oriented in a c-axis, Msmax≧1.5×Msmin being satisfied, Ms being the metallic element of riot larger of R(M1) or R(M3), Msmax and Msmin respectively being a maximum value and minimum value of a concentration of Ms at a position at 50% of an average film thickness of a cross section including the c-axis.

6 . The oxide superconductor according to claim 5 , wherein Msmax≧2.3×Msmin is satisfied.

7 . The oxide superconductor according to claim 5 , wherein the oxide layer is provided on a base member, or the oxide layer is provided on an intermediate layer provided on the base member.

8 . The oxide superconductor according to claim 5 , wherein the M1 is Pr, Nd, or Sm.

9 . A method for manufacturing an oxide superconductor, comprising:
forming an oxide superconductor as a film by making a gel film using a methanol solution, by obtaining a pre-bake film of an oxide and fluoride by decomposing a trifluoroacetic acid group in a pre-bake process, by forming a perovskite structure having a number of oxygen atoms of 6.0 in a main bake in a humidified atmosphere of 725 to 850 degrees C., and by performing oxygen annealing, the methanol solution having metal trifluoroacetate hydrate as a major component, a mole ratio of metallic, elements of RE:Ba:Cu being 1:2:3, at least three types of elements, selected from Pr, Nd, Sm, Eu, Gd, Y, Tb, Dy, Ho, Er, Tm, Yb, and Lu being included as the RE, the elements being M1, M2, and M3 in the listed order, R(M1)≦20 mol % and R(M2)≧60 mol % and R(M3)≦20 mol % being satisfied to obtain REBa 2 Cu 3 O 7-x having a single perovskite structure oriented in a c-axis R(M1) being an average metallic element ratio of M1 in M1+M2+M3,
1 SD(Ms)>0.15 being satisfied, Ms being the metallic element of not larger of R(M1) or R(M3), SD(Ms) being a standard deviation of concentration values of Ms over the average value of the Ms concentration at a position at 50% of an average film thickness of a cross section including the c-axis.

10 . The method for manufacturing the oxide superconductor according to claim 9 , wherein the M1 is Pr, Nd, or Sm.

11 . The method for manufacturing the oxide superconductor according to claim 9 , wherein the first film is provided on a base member included in the base body, or the first film is provided on an intermediate layer provided on the base member.

12 . The method for manufacturing the oxide superconductor according to claim 9 , wherein high purification processing of the solution is performed.

13 . The method for manufacturing the oxide superconductor according to claim 9 , wherein the solution is made by processes including a process using pentafluoropropionic acid, and a process of substituting trifluoroacetic acid for at least a portion of the pentafluoropropionic acid after the process using the pentafluoropropionic acid.

Assignees

• Toshiba Kk

Inventors

• Araki Takeshi
• Hayashi Mariko
• Fuke Hiroyuki

Classifications

• C04B2235/3215

  Barium oxides or oxide-forming salts thereof · CPC title

• C04B35/624

  Sol-gel processing · CPC title

• C04B2235/724

  Halogenide content · CPC title

• C04B2235/3224

  Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide · CPC title

• C04B2235/721

  Carbon content · CPC title