Superconducting Properties of BiPbSrCsCuO and BiSrCaCuO Glass-Ceramics

In this work we study the main differences between the superconducting properties of the Bi$\text{}_{4}$Sr$\text{}_{3}$Ca$\text{}_{3}$Cu$\text{}_{4}$O$\text{}_{x}$ and (Bi$\text{}_{0.8}$Pb$\text{}_{0.2}$)$\text{}_{4}$Sr$\text{}_{3}$Ca$\text{}_{3}$Cu$\text{}_{4}$O$\text{}_{x}$ glass-ceramics. The Bi$\text{}_{4}$Sr$\text{}_{3}$Ca$\text{}_{3}$Cu$\text{}_{4}$O$\text{}_{x}$ and (Bi$\text{}_{0.8}$Pb$\text{}_{0.2}$)$\text{}_{4}$Sr$\text{}_{3}$Ca$\text{}_{3}$Cu$\text{}_{4}$O$\text{}_{x}$ glass-ceramics prepared in the same conditions contain similar amounts of the superconducting 2212 phase, however their superconducting and normal-state electrical properties differ significantly. The main reason which makes BiSrCaCuO glass-ceramics worse superconductor than BiPbSrCaCuO is its microstructure.