Synthesis of HgPb1223 superconductor

The synthesis and processing parameters that affect the phase purity and gr ain growth of Pb-doped Hg1223 were optimized. Samples were prepared from co mmercial BaCaCuO precursors using CaHgO2 as the external Hg-source. Samples were quenched from high temperature at different stages of the reaction an d their microstructures were investigated. The reaction and annealing condi tions were optimized to improve the phase purity and microstructural homoge neity. The as-synthesized HgPb1223 samples were shown to be optimally doped and to exhibit T-c values in the range of 130-134 K. Postannealing of the samples in flowing oxygen or argon at 300-400 degrees C did not improve T-c and deteriorated the magnetic hysteresis.