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

Abstract

BiPb-2212 phase in nanoscale was added to BiPb-2223 phase with a general stoichiometry of (Bi[Formula: see text]Pb[Formula: see text]Sr[Formula: see text]Ca[Formula: see text]Cu[Formula: see text]O[Formula: see text]/Bi[Formula: see text]Pb[Formula: see text]Sr[Formula: see text]Ca[Formula: see text]Cu[Formula: see text]O[Formula: see text], 0.0 [Formula: see text] x [Formula: see text] 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 [Formula: see text] for all samples. The highest critical current density [Formula: see text] was recorded for the sample with x = 1.5 wt.%. The normalized excess conductivity [Formula: see text] 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 [Formula: see text], interlayer coupling strength s, Fermi velocity [Formula: see text] of the carriers and Fermi energy [Formula: see text] were calculated for both samples with x = 0.0 wt.% and 1.5 wt.%.