Improving the Physical Properties of (Bi, Pb)-2223 Phase by SnO_2 Nano-particles Addition

摘要

In this work, the effect of SnO_2 nano-particles (40 nm) addition to the physical properties of Bi_(1.6)Pb_(0.4)Sr_2Ca_2Cu_3O_(10+δ) superconducting phase was studied. (Bi, Pb)-2223 superconductor phase added by SnO_2 nano-particles was prepared by a conventional solid-state reaction technique. The SnO_2 nano-particles concentrations x varied from 0.0 to 2.0 wt% of the sample's total mass. The prepared samples were investigated by X-ray powder diffraction (XRD), scanning electron microscope (SEM) and electron dispersive spectroscopy (EDS) for analyzing phase formation and microstructure. Also, the electrical resistivity and transport critical current density, for investigated samples, were measured by standard dc four-probe method. Phase examination by XRD indicated that SnO_2 nano-particles enhanced the (Bi, Pb)-2223 phase formation up to x = 0.4 wt%. On the other hand, the high concentrations of SnO_2 nano-particles retarded the phase formation. Granular investigation, from scanning electron microscope, showed that both number and size of voids decreased as x increased from 0.0 to 0.4 wt%. The superconducting transition temperature and transport critical current density were found to have optimal values at x = 0.4 wt%. The enhancement rates in T_c and J_c were 12 and 58%, respectively, which had a maximum enhancement in both J_c and T_c for all investigated nano-particles.