Superconductivity investigation of (Bi, Pb)-2223 added with different nanoferrites and their composites

Abstract

Abstract In this study, the impact of different types of nanoferrites additions of Zn0.5Ni0.5Fe2O4 and Ba0.4Sr0.4Ca0.2Fe12O19 nanoparticles and their nanocomposite of (Zn0.5Ni0.5Fe2O4)0.5 (Ba0.4Sr0.4Ca0.2Fe12O19)0.5 on the structural and normal state resistivity of Bi1.6Pb0.4Sr2Ca2Cu3O10, ((Bi,Pb)-2223) superconducting phase were systematically investigated. The samples were synthesised using high purity oxide powders via a solid-state reaction approach. Based on the Rietveld analysis of x-ray diffraction (XRD) data, the tetragonal structure of (Bi,Pb)-2223 was established to be the predominant phase for all composite samples of the three nano-additions’ contents. However, a little change to the lattice parameters ( a and c ) was obtained. Furthermore, the small amounts (0.04 wt%) of Ba0.4Sr0.4Ca0.2Fe12O19 and (Zn0.5Ni0.5Fe2O4)0.5(Ba0.4Sr0.4Ca0.2Fe12O19)0.5 improved the development of the (Bi,Pb)-2223 phase. The volume fraction of the (Bi,Pb)-2223 phase increased from 86.47% to 88.73% and 88.69%, respectively. Then, it declined to 74.25% and 71.48% upon rising x to 0.40 wt%, respectively, as well as for Zn0.5Ni0.5Fe2O4 nanoparticles up to 0.40 wt%. SEM images verify the host superconducting matrix’s granular structure for all three nanoadditions up to 0.40 wt%. The existence of three nano additions in the host superconductor matrix is verified by employing energy dispersive x-ray (EDX) and x-ray photoelectron spectroscopy (XPS) analysis. The measurements for the resistivity dependency of temperature presented that, as compared to the pure sample (Tc = 108.67 K), the nano-(Zn0.5Ni0.5Fe2O4) x added in the (Bi,Pb)-2223 phase exhibits more negative impact than it is with the other two additions. In contrast, the nano-(Ba0.4Sr0.4Ca0.2Fe12O19) x has the highest value of Tc with a value of 110.95 K at x = 0.04 wt%. Furthermore, the superconducting transition width (∆Tc) improved for all composite samples except for the sample at x = 0.04 wt%, for Ba0.4Sr0.4Ca0.2Fe12O19 and (Zn0.5Ni0.5Fe2O4)0.5 (Ba0.4Sr0.4 Ca0.2Fe12O19)0.5 which showed the sharpest transition width. This suggests that their addition is anticipated to act as artificial pinning centers and strengthen the coupling between the grains in the (Bi,Pb)-2223 ceramic.