Preparation and Properties of Doped Hg-Based Superconducting Copper Oxides

Synthesis of Pb, Fe and Cd doped Hg-based $HgBa_{2}Ca_{2}Cu_{3}O_{8 + δ}$ (Hg-1223) superconducting ceramics was performed. Hg-free precursor $Ba_{2}Ca_{2}Cu_{3}O_{8 + δ}$ with high chemical homogeneity and reactivity obtained by the sol-gel method was used. The superconducting and impurity phases were determined by means of scanning electron microscopy and microprobe analysis. The results of resistivity and magnetization measurements for different kinds of doped elements were presented.