Synthesis of yttrium barium cuprate by coprecipitation of oxalates
- Institute of Solid-State Chemistry, Ekaterinburg (Russian Federation)
- POZ REDMET Joint-Stock Co., Pyshma (Russian Federation)
A solid-state reaction between Y{sub 2}O{sub 3}, CuO, and BaCO{sub 3} is the most-used process for producing YBa{sub 2}Cu{sub 3}O{sub 7-x} (1-2-3) high-{Tc} materials. As a rule, formation of the 1-2-3 phase is carried out at a temperature no higher than 975{degrees}C in order to avoid incongruent melting of the compound. This temperature is well below the dissociation temperature of BaCO{sub 3} (1400-1450{degrees}C); therefore, multiple sintering-grinding cycles are necessary to produce single-phase samples. As a result, the labor required for the process increases sharply, and the product is contaminated with different elements. The low rate of reaction of BaCO{sub 3} with CuO and Y{sub 2}O{sub 3} is a reason for the prolonged formation of 1-2-3. The authors demonstrated advantages of using Y, Ba and Cu oxalates as starting components for producing high-T{sub c} materials over using Y and Cu oxides and barium carbonate. Admixing of individual oxalates that were found by chemical analysis to be deficient in the coprecipitated mixture simplifies the preparation of the high-T{sub c} materials. The proposed process can be applied both to manufacture of high-T{sub c} materials and regeneration of waste products formed in the process. A single stage synthesis with optimal reaction conditions was found that significantly reduced the impurity content of YBa{sub 2}Cu{sub 3}O{sub 7-x}.
- OSTI ID:
- 98714
- Journal Information:
- Inorganic Materials, Journal Name: Inorganic Materials Journal Issue: 8 Vol. 30; ISSN 0020-1685; ISSN INOMAF
- Country of Publication:
- United States
- Language:
- English
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