Structural, electrical, and thermal properties of Ba-substituted B(Pb)SCCO superconductors prepared by sol-gel method

In this study, some physical properties of BSCCO superconductors have been investigated. The effects of Ba substitution in Bi_1.7Pb_0.3Sr_2-yBa_yCa₂Cu₃O_10+δ superconductor synthesized by the sol-gel method on the structural, thermal, and superconducting properties were identified. X-ray diffraction patterns display the dominant Bi-2223 high-temperature phase (HTP) mixed with the Bi-2212 low-temperature phase (LTP) in all samples. Variations in lattice parameters (a, b and c) significantly affect sample properties such as lattice volume, c/a ratio, and molecular weight (w). The highest percentage of HTP% appeared at y = 0.1 Ba content. Transmission Electron Microscopy (TEM) displays the formation of rod-like structures with nanoscale lengths. The Ba substitution ratio significantly determines the lattice dimension and oxygen content, affecting the prepared superconductor’s transition temperature (Tc). Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) show the changes in mass loss and shifting in decomposition temperatures correlated with the Ba substitution rate. The optimal ratio of Ba was at y = 0.1, which exhibits the highest HTP percentage of 73.07% and the highest T_c of 113.5 K, suggesting improved superconducting properties.