Rapid formation of the Bi2-xPbxSr2Ca2Cu3Oy high Tc-phase, using spray-dried nitrate precursor powders

This study describes the use of spray-dried nitrate precursor powders in the synthesis of Bi-2223 high Tc-superconductors. The decomposition of the precursor powder is studied using TGA/DTA, XRD, IR, and nitrogen analyses. The particle size is determined using SEM. The low decomposition temperature of the nitrates (∼600 °C) and the small particle size of the spray dried powder (∼ 3·10−6 m), resulting in a lowering of the calcination temperature and a shortening of the sinter time, enabled us to synthesize a >96% pure Bi-2223 phase (from XRD peak intensities) after a thermal process of 5h at 650 °C and 60 h at 855 °C.