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EP0347770A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Process of producing a bismuth system oxide superconductor

Assignee: Daikin Industries Ltd
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Filing: 1989-06-16
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Granted: —
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Expires: 2009-06-16
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Abstract

Abstract A bismuth system oxide superconductor comprising the 11) K phase is effectively prepared by a process compri­sing steps of mixing a bismuth compound, a strontium com­pound, a calcium compound, a copper compound and optionally a lead compound, optionally provisionally sintering the mixture, and sintering the mixture.

Inventors

  • 👤 Utako C/O Yodogawa Works Of Daikin Endo
  • 👤 Satoshi Koyama
  • 👤 Kazuo Okamura
  • 👤 Tomoji C/O Osaka University Sangyo Kawai
  • 👤 Koichi Kitazawa

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 07:09
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/80; H10N60/85; H10N60/855; H10N60/857; C; C04; C04B; C04B35/00; C04B35/01; C04B35/45; C04B35/4521; C04B35/4525; H10N60/01; H10N60/0268; Y; Y02; Y02E; Y02E40/00; Y02E40/60; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/737; Y10S505/775; Y10S505/776; Y10S505/782

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 63 words
A bismuth system oxide superconductive mate­rial comprising bismuth, lead, strontium, calcium, copper and oxygen atoms, the X-ray diffraction pattern of which measured with the Cu-K α line has a diffraction line at 2ϑ of about 4.7°, wherein neither of the diffraction lines at 2ϑ of about 5.7° and about 7.2° has intensity larger than 5 % of that at 2ϑ of about 4.7°.
Claim 2
Dependent Claim 63 words
A bismuth system oxide superconductive mate­rial comprising bismuth, lead, strontium, calcium, copper and oxygen atoms, the X-ray diffraction pattern of which measured with the Cu-K α line has a diffraction line at 2ϑ of about 4.7°, wherein neither of the diffraction lines at 2ϑ of about 5.7° and about 7.2° has intensity larger than 5 % of that at 2ϑ of about 4.7°.
Claim 3
Dependent Claim 28 words
The bismuth system oxide superconductive mate­rial according to claim 1, wherein no diffraction line appears at 2ϑ of about 5.7° or about 7.2° in the X-ray diff­raction pattern.
Claim 4
Dependent Claim 117 words
The bismuth system oxide superconductive mate­rial according to claim 1, which has the composition of Bi x Pb y (Sr u Ca v Cu w ) z O α wherein x is a number of from 0.150 to 0.215, y is a number of 0.030 to 0.090 and z is a number of 0.720 to 0.800 pro­vided that the sum of x, y and z is 1 (one); u is a number of from 0.200 to 0.290, v is a number of from 0.250 to 0.355 and w is a number of from 0.430 to 0.530 provided that the sum of u, v and w is 1 (one); and α is a number from 0.8 to 1.3.
Claim 5
Dependent Claim 117 words
The bismuth system oxide superconductive mate­rial according to claim 2, which has the composition of Bi x Pb y (Sr u Ca v Cu w ) z O α wherein x is a number of from 0.150 to 0.215, y is a number of 0.030 to 0.090 and z is a number of 0.720 to 0.800 pro­vided that the sum of x, y and z is 1 (one); u is a number of from 0.200 to 0.290, v is a number of from 0.250 to 0.355 and w is a number of from 0.430 to 0.530 provided that the sum of u, v and w is 1 (one); and α is a number from 0.8 to 1.3.
Claim 6
Dependent Claim 24 words
The bismuth system oxide superconductive mate­rial according to claim 1, wherein the X-ray diffraction pattern has no diffraction line to be assigned to impuri­ties.
Claim 7
Dependent Claim 24 words
The bismuth system oxide superconductive mate­rial according to claim 2, wherein the X-ray diffraction pattern has no diffraction line to be assigned to impuri­ties.
Claim 8
Dependent Claim 114 words
The bismuth system oxide superconductive mate­rial according to claim 5, which has the composition of Bi x Pb y (Sr u Ca v Cu w ) z O α x is a number of from 0.185 to 0.210, y is a number of 0.030 to 0.050 and z is a number of 0.750 to 0.770 provided that the sum of x, y and z is 1; u is a number of from 0.255 to 0.290, v is a number of from 0.275 to 0.310 and w is a number of from 0.430 to 0.455 provided that the sum of u, v and w is 1; and α is a number from 0.8 to 1.3.
Claim 9
Dependent Claim 116 words
The bismuth system oxide superconductive mate­rial according to claim 6, which has the composition of Bi x Pb y (Sr u Ca v Cu w ) z O α wherein x is a number of from 0.150 to 0.215, y is a number of 0.030 to 0.090 and z is a number of 0.720 to 0.800 pro­vided that the sum of x, y and z is 1 (one); u is a number of from 0.200 to 0.290, v is a number of from 0.250 to 0.355 and w is a number of from 0.430 to 0.530 provided that the sum of u, v and w is 1 (one); and αis a number from 0.8 to 1.3.
Claim 10
Dependent Claim 49 words
The bismuth system oxide superconductive mate­rial according to claim 1, which further comprises a super­conductive phase having a critical temperature in a range from 90 K to 100 K and the diffraction line at 2ϑ of about 4.7° in the X-ray diffraction pattern measured with the Cu-K α line.
Claim 11
Dependent Claim 49 words
The bismuth system oxide superconductive material according to claim 2, which further comprises a superconductive phase having a critical temperature in a range from 90 K to 100 K and the diffraction line at 2ϑ of about 4.7° in the X-ray diffraction pattern measured with the Cu-K α line.
Claim 12
Dependent Claim 85 words
A bismuth system oxide superconductive mate­rial comprising bismuth, lead, strontium, calcium, copper and oxygen atoms, the X-ray diffraction pattern of which measured with the Cu-K α line has a diffraction line at 2ϑ of about 4.7°, wherein at least one of the diffraction lines at 2ϑ of about 5.7° and about 7.2° has intensity larger than 5 % of that at 2ϑ of about 4.7° and the superconductive mate­rial contains a phase having a critical temperature in a range from 90 K to 100 K.
Claim 13
Dependent Claim 85 words
A bismuth system oxide superconductive mate­rial comprising bismuth, lead, strontium, calcium, copper and oxygen atoms, the X-ray diffraction pattern of which measured with the Cu-K α line has a diffraction line at 2ϑ of about 4.7°, wherein at least one of the diffraction lines at 2ϑ of about 5.7° and about 7.2° has intensity larger than 5 % of that at 2ϑ of about 4.7° and the superconductive mate­rial contains a phase having a critical temperature in a range from 90 K to 100 K.
Claim 14
Dependent Claim 41 words
A process for producing a bismuth system oxide superconductor, which process comprising steps of mixing a bismuth compound, a strontium compound, a calcium compound, a copper compound and optionally a lead compound, optionally provisionally sintering the mixture, and sintering the mixture.
Claim 15
Dependent Claim 41 words
A process for producing a bismuth system oxide superconductor, which process comprising steps of mixing a bismuth compound, a strontium compound, a calcium compound, a copper compound and optionally a lead compound, optionally provisionally sintering the mixture, and sintering the mixture.
Claim 16
Dependent Claim 41 words
The process according to claim 12, at least the copper compound is copper nitrate, and all the compounds are dissolved or dispersed in a medium, the medium is remo­ved and then the nitrate is thermally decomposed to mix the compounds homogeneously.
Claim 17
Dependent Claim 36 words
The process according to claim 13, wherein all the compounds are nitrates, and the nitrates are dissol­ved in a medium, the medium is removed and then the nitrates are thermally decomposed to mix the compounds homogeneously.
Claim 18
Dependent Claim 19 words
The process according to claim 12, wherein an oxygen partial pressure during sintering is not higher than 0.15 atm.
Claim 19
Dependent Claim 19 words
The process according to claim 13, wherein an oxygen partial pressure during sintering is not higher than 0.15 atm.
Claim 20
Dependent Claim 19 words
The process according to claim 14, wherein an oxygen partial pressure during sintering is not higher than 0.15 atm.

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