| 摘要 |
PURPOSE:To obtain the subject superconductor which can be easily sintered and has excellent uniformity and stability, high purity and dense texture, by mixing a carbon-containing substance to an acidic aqueous solution containing ions of Bi, Ca, Sr and Cu, drying and heat-treating the obtained slurry mixture and forming and sintering the treated product. CONSTITUTION:An aqueous solution acidified with acetic acid, peracid and/or nitric acid and containing ions of Bi, Ca, Sr and Cu (e.g. an aqueous solution of acetic acid containing Bi2O3, CaCO3, SrCO3 and CuO having purities of >=99% and having total metal ion concentration of 50-10<-4>mol./l) is mixed with several-several hundred wt.% of a carbon-containing substance such as carbon, PVA or cellulose and, as necessary, an organic solution such as alcohol to obtain a slurry or sludgy mixture. The mixture is dried at <=100 deg.C and calcined in an O2-containing atmosphere at 200-900 deg.C. The calcined product (powder) is formed and sintered in an O2-containing atmosphere at 600-920 deg.C for several-several tens hour to obtain the objective superconductor composed of 12-40mol.% of Bi, 16-67mol.% of Ca+Sr and 11-67mol.% of Cu and containing the molar number of 0atom. corresponding 1.0-1.4 times the total molar number of the metallic elements. |
