فهرست نشریات علمی دسترسی آزاد ایران

This research investigates the substitution of conventional lead oxide with a lead oxide-silica vitreous composite in the fabrication of Bi2223 superconducting materials. The traditional Bi1.6Pb0.4Sr2Ca2Cu2O10+x formulation relies heavily on lead oxide to optimize phase formation and enhance superconducting properties. However, environmental and health concerns associated with lead oxide necessitate the development of alternative approaches. In this work, a 1:1 molar ratio of SiO2-PbO-based glassy matrix was employed as a partial replacement for pure PbO, maintaining 0.4 mole equivalents to achieve the target superconductor stoichiometry. The synthesized samples were characterized through X-ray diffraction analysis, scanning electron microscopy, and differential thermal analysis to evaluate structural characteristics and phase purity. Superconducting performance was assessed by measuring critical temperature and critical current density. Experimental results demonstrate that incorporation of the PbO–SiO₂ vitreous composite increases the Bi2223 phase fraction from 76.8% (conventional PbO) to 89.7%, while enhancing the critical temperature (Tc) by ~2.3 K. This suggests improved phase purity and superconducting performance, attributable to controlled Pb release and enhanced microstructural alignment. This lead-silica frit system presents notable benefits—such as lower toxicity and the flexibility to integrate functional additives like flux enhancers and mechanically stable layered structures—offering a more cost-effective and eco-friendly route for HTS synthesis.