Synthesis and properties of Bi1.6Pb0.4Sr2-xCa2Cu3Oy

Bi1.6Pb0.4Sr2-xCa2Cu3Oy (x = 0, 0.2, 0.4) high-T-c materials were prepared from oxide-carbonate mixtures and presynthesized mixed oxides. The 2223 sup erconducting phase was found to be formed most rapidly in the x = 0.4 sampl e if the Pb- and Ca-containing starting reagents were separated in the init ial stage of synthesis. The highest superconducting transition temperature, T-c(R = 0)= 104.3 K, was attained in the stoichiometric 2223 material. The materials were characterized by electrical resistivity, magnetic susceptib ility, and Hall effect measurements. The Hall data were used to evaluate ca rrier concentration and mobility. The 77-K resistivity of the materials was measured as a function of magnetic field.