Conductivity and Superconductivity of (Bi,Pb)$\text{}_{4}$Sr$\text{}_{3}$Ca$\text{}_{3}$Cu$\text{}_{4}$O$\text{}_{x}$ Glass-Ceramics

(Bi,Pb)-Sr-Ca-Cu-O glasses, annealed in proper conditions, transform into a granular metal and superconductor. As a result of annealing oxide superconductors belonging to the bismuth family (Bi,Pb)$\text{}_{2}$Sr$\text{}_{2}$CuO$\text{}_{x}$, (Bi,Pb)$\text{}_{2}$Sr$\text{}_{2}$ CaCu$\text{}_{2}$O$\text{}_{x}$, and (Bi,Pb)$\text{}_{2}$Sr$\text{}_{2}$Ca$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{x}$ crystallize. (Bi,Pb)-Sr-Ca-Cu-O glass-ceramic samples were obtained by annealing the amorphous solid at temperatures between 500°C and 870°C. Their microstructure was studied with scanning electron microscopy, atomic force microscopy, and X-ray diffraction. The temperature dependence of resistivity in annealed samples was studied in a temperature range from 3 K to 300 K. In this work we present the influence of the microstructure on the electrical properties of the granular and disordered material composed of the 2201 and 2212 grains embedded in the nonmetallic matrix