Effects of diverse nanoparticles co-introduction on superconducting traits of YBa₂Cu₃O_7-d ceramics: A comparative analysis

Investigating the impact of co-introducing two distinct types of nanoparticles (NPs) with specific characteristics into high-temperature YBa₂Cu₃O_7-d (Y123) superconductor ceramics is an engaging area of research. In this work, we used Ag and PbO NPs as the primary additives, while Al₂O₃, Dy₂O₃, SiO₂, and WO₃ NPs served as secondary additives. Two separate sample sets (identified as Ag-sample set and PbO-sample set) were produced via solid-state thermal sintering to comparatively evaluate the effectiveness of this dual-additive approach on the superconductivity of Y123 ceramics. Samples were subjected to comprehensive structural characterizations using X-ray diffraction (XRD) and scanning electron microscopy (SEM), and transport characterization using PPMS (Physical Property Measurement System) to measure resistivity-temperature (ρ-T), a.c susceptibility (χ-T), and d.c magnetization (M-H). The co-introduction of NPs was found to have a positive impact on the superconductivity and pinning capabilities of Y123. Well-oxygenated orthorhombic superconducting materials with onset critical temperature (T_c^on) of around 93.2 K were successfully produced. Importantly, the presence of PbO-NPs with specific other NPs (like SiO₂ and WO₃) proved to be more effective than the presence of Ag-NPs in enhancing critical current density (J_c) and pinning energy. Notably, the PbO-WO₃ sample exhibited the highest value of J_c = 6000 A/cm². Ag-NPs demonstrated their great effectiveness in upgrading the assemblage of grains and reinforcing their connectivity. The incorporation of both PbO and Ag with secondary oxide NPs created better pinning configurations, increasing, for instan_ce, the J_c value by more than a factor of 5 for an applied field up to 1 Tesla for the PbO-WO₃ sample in comparison to the non-added control sample. These findings have the potential to contribute to the advancement of second-generation high-temperature superconductor technologies.