Abstract
The effects of Ba-addition to the high-Tc phase in the Bi-Pb-Sr-Ca-Cu-O system have been studied for starting compositions of Bi:Pb:(Sr1-x, Bax):Ca:Cu=0.96:0.24:1.0:1.0:1.6 with x=0 to 0.30 heated at 845 or 850°C. The characterization of the samples has been made by XRD, DTA, the measurements of DC electrical resistivity and AC susceptibility, SEM and WDX. The Ba-addition in the range of 0.005≤x≤0.10 promotes the formation of the high-Tc phase due to lowering of the partial melt. Tc increases to 112K for the sample with low Ba contents, while Ba-free sample exhibits Tc=106K. The tetragonal lattice constants are a=5.412 Å for all samples, but c=37.10 Å and 37.20 Å for x=0 and 0.2, respectively. WDX experiments clearly reveals that the high-Tc phase contains a small amount of Ba as a solid solution.
