Doping of (Bi,Pb)-2223 with metal oxides

The effect of doping on formation, superconductivity and pinning forces of (Bi,Pb)-2223 was studied for several dopants. They can be subdivided into promoters (Cu, Mn at low doping level of x = 0.1 and Rh) and inhibitors (Mg, Al, Sn, Co, Y, Pd and high substitution levels of Mn and Ni) of the transformation of the precursor material into (Bi,Pb)-2223. According to X-ray diffraction (XRD) studies the incorporation of the dopant into the 2223 lattice is restricted to a very low doping level. Higher dopant concentrations are accompanied by a segregation of secondary phases. These segregations are not effective in the process of creating flux pinning centres. A depression of Tc is observed for 2223 materials with the dopants Co, Ni and Pd.