Publication Details
Abstract
This study investigates the influence of annealing temperature on the structural and superconducting characteristics of Bi₂Sr₂Ca₃Cu₄O₁₀₊δ high-temperature superconductors synthesized using the solid-state reaction method. Samples were annealed at 650°C, 750°C, and 850°C in an oxygen-rich atmosphere to control phase formation, crystal structure, and superconducting behavior. X-ray diffraction (XRD) analysis confirmed a progressive transformation from low-CuO₂-layer phases to the Bi-2234 phase, with an optimal c/a ratio and crystallite size observed at 850°C. Electrical measurements showed enhanced superconductivity at 850°C, with a sharp transition temperature (T_c(on) = 115.8 K) and narrow ΔT_c, indicating high phase purity. SEM and AFM analyses revealed improved grain connectivity, reduced surface roughness, and enhanced structural uniformity at elevated temperatures. The results confirm that 850°C is the optimal annealing temperature for achieving superior structural integrity and superconducting performance in Bi-2234 compounds.