Effect of nano BiPb-2212 phase addition on BiPb-2223 phase properties

摘要

BiPb-2212 phase in nanoscale was added to BiPb-2223 phase with a general stoichiometry of (Bi1.7Pb0.4Sr2.1Ca1.1Cu2.1O8+delta)(x)/Bi1.8Pb0.4Sr2.0Ca2.0Cu3.2O10+delta, 0.0 = x = 2.5 wt.%. All samples were prepared by the standard solid-state reaction method. The prepared nano BiPb-2212 phase was characterized by X-ray powder diffraction (XRD) and transmission electron microscope (TEM). The prepared samples were characterized by XRD and the scanning electron microscope (SEM). XRD analysis indicated that the sample with x = 1.5 wt.% has the highest relative volume fraction for BiPb-2223 phase. Samples were examined by electrical resistivity and I V measurements. There is no significant change in the superconducting transition temperature T-c for all samples. The highest critical current density J(c) was recorded for the sample with x = 1.5 wt.%. The normalized excess conductivity (Delta sigma/sigma(room)) was calculated according to Aslamazov Larkin (AL) model. Four different fluctuating regions were recorded as the temperature decreased. The coherence length along the c-axis at 0 K xi(c)(0), interlayer coupling strength s, Fermi velocity v(F) of the carriers and Fermi energy E-F were calculated for both samples with x = 0.0 wt.% and 1.5 wt.%.