Synthesis of HgPb1223 superconductor

The synthesis and processing parameters that affect the phase purity and grain growth of Pb-doped Hg1223 were optimized. Samples were prepared from commercial BaCaCuO precursors using CaHgO/sub 2/ as the external Hg-source. Samples were quenched from high temperature at different stages of the reaction and their microstructures were investigated. The reaction and annealing conditions were optimized to improve the phase purity and microstructural homogeneity. The as-synthesized HgPb1223 samples were shown to be optimally doped and to exhibit T/sub c/ values in the range of 130-134 K. Post-annealing of the samples in flowing oxygen or argon at 300-400/spl deg/C did not improve T/sub c/ and deteriorated the magnetic hysteresis.