| 摘要 |
PURPOSE:To enhance crystallinity by calcining the oxides or carbonates of Bi, Sr, Ca and Cu and sintering the resulting precursor at a temp. above the calcining temp. CONSTITUTION:Bi2O3, SrCO3, CaCO3 and CuO are weighed so as to regulate the molar ratio of Bi:Sr:Ca:Cu to 2:2:1:2 and they are wet-mixed. This powdery mixture is dried with hot air and calcined at 700-800 deg.C in a muffle furnace to form a precursor based on (2201) phase. This precursor is sintered at 820-880 deg.C to obtain an oxide superconductor made of (2212) phase, contg. Bi, Sr, Ca and Cu in 2:2:1:2 molar ratio and having satisfactory crystallinity. |
