Investigation of Physical Properties of (Nano-SmIG)/(Bi, Pb)-2212 Phase

In this study, the impact of adding samarium iron garnet (Sm3Fe5O12; SmIG) nanoparticles to the (Bi1.6Pb0.4)Sr1.9Ca0.9Y0.2Cu2.1O8+delta ((Bi, Pb)-2212) superconductor was investigated. The conventional solid-state reaction method was utilized to synthesize (SmIG)x(Bi, Pb)-2212 phase with different concentrations (x = 0, 0.25, 0.5, 0.75, 1, and 2 wt%). The structure, the morphology, and the elemental composition were tested using X-ray powder diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and dispersive X-ray spectroscopy (EDX), respectively. Filling of pores and voids validated the impact of the added nano-SmIG on intergrain connections. The enhancement in oxygen content was verified by iodometric titration analysis. The superconducting transition temperature (Tc) and the critical current density (Jc) showed best enhancement with the addition of nano-SmIG up to x = 0.75 wt%, having values of 91.02 K and 373.95 A/cm2, respectively. The fluctuations in the superconducting properties were explained via X-ray photoelectron spectroscopy (XPS) by studying the elemental composition and oxidation states for all elements. Vickers microhardness (Hv) investigations were carried out at different applied loads and indentation time of 20 s, where Hv reached its highest value at x = 0.25 wt%. Based on Hv values, the modified proportional sample resistance (MPSR) model offered the most suitable theoretical model to elucidate the experimental data.