Effects of Electron, Gamma and Neutron Irradiation on the Superconducting Properties of (Bi,Pb)₂Sr₂Ca₂Cu₃O_x Bulk Samples

In this study, we explored the potential of irradiation techniques to optimize defect concentration and crystal structure in (Bi,Pb)₂Sr₂Ca₂Cu₃O₁₀ (Bi-2223) superconductors, aiming to enhance their practicality by potentially improving their critical temperature (Tc) in high magnetic fields. Bi-2223 superconductors have higher Tc and less stringent cooling requirements than low-temperature types, yet enhancing Tc under high magnetic fields is still challenging. The study meticulously compared the electrical properties of Bi-2223 samples in bulk form, subjected individually to electron, gamma, and neutron irradiations, prepared via the conventional solid-state reaction method. Subsequent analyses of structural properties through X-ray diffraction revealed changes in cell lattice parameters, while electrical resistance and AC susceptibility measurements provided insights into the critical temperature. Interestingly, a significant decrease in Tc was observed across all irradiated samples instead of an enhancement, challenging our initial hypothesis. Electron and gamma irradiations led to more homogeneously distributed and less porous defects compared to neutron irradiation, which correlated with the observed decrease in Tc—22.9% for neutron, 16.7% for gamma, and 13.5% for electron irradiation. These results highlight the intricate relationship between the type and distribution of defects induced by different irradiations and their varying impacts on superconductor performance. This study illustrates how defects, based on their characteristics, distinctly affect superconducting properties, emphasizing the complexity of defect interactions in superconductors. Our findings highlight the crucial relationship between irradiation-induced defects and the superconducting properties of Bi-2223, suggesting that the impact of Tc reduction on high-temperature superconductor applications needs to be reevaluated.