Process for preparing homogenous superconductors by heating in a nitrogen dioxide containing atmosphere
This patent describes a process for preparing homogeneous superconducting MBa{sub 2}Cu{sub 3}O{sub x}, wherein M is at least one element chosen from the group consisting of Y, La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu, and x is from about 6.5 to about 7.0. It comprises heating at least one starting material selected from the group consisting of MBa{sub 2}Cu{sub 3}O{sub x}, MBa{sub 2}Cu{sub 3}O{sub y} wherein y is from about 6.0 to about 6.5, and a mixture of M-, Ba- and Cu-containing MBa{sub 2}Cu{sub 3}O{sub x} precursors, the mixture having an M:Ba:Cu atomic ratio of about 1:2:3 in the presence of an atmosphere containing at least about 1% nitrogen dioxide at a temperature of from about 600{degrees} C to about 1000{degrees} C for at least about one hour; heating the product in the presence of an oxygen-containing atmosphere at a temperature of from about 700{degrees} C to about 975{degrees} C for at least about one-half hour; and maintaining the product in the presence of an oxygen-containing atmosphere while cooling for a time sufficient to obtain the MBa{sub 2}Cu{sub 3}O{sub x}.
- Assignee:
- E.I. Du Pont de Nemours and Co., Wilmington, DE (United States)
- Patent Number(s):
- US 5079217; A
- Application Number:
- PPN: US 7-478063
- OSTI ID:
- 5653512
- Resource Relation:
- Patent File Date: 7 Feb 1990
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BARIUM OXIDES
SYNTHESIS
COPPER OXIDES
RARE EARTH COMPOUNDS
HEATING
HIGH-TC SUPERCONDUCTORS
MIXTURES
NITROGEN DIOXIDE
OXYGEN
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
DISPERSIONS
ELEMENTS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
OXIDES
OXYGEN COMPOUNDS
SUPERCONDUCTORS
TEMPERATURE RANGE
TRANSITION ELEMENT COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication