Synthesis and properties of doped HgBa2Ca2Cu3O8+δ superconductors

Synthesis of HgBa2Ca2Cu3O8+δ (Hg-1223) with higher chemical homogeneity and large reactivity of precursor powder Ba2Ca2Cu3O8+δ was carried out. Pb, Fe and Cd doped HgBa2Ca2Cu3O8+δ were prepared with using Hg-free precursor Ba2Ca2Cu3O8+δ obtained by the sol-gel method. After synthesis the samples were in the state overdoped with oxygen and reach the optimum state in flowing argon. The temperature dependences of the resistivity and magnetization measurements for different kinds of doped elements are presented.