Investigation of Sm → Ca substitution in Bi(Pb)SrCaCuO high temperature superconductor by low field AC magnetic susceptibility

Abstract

We have investigated the effect of Sm substitution in Bi(Pb)SrCaCuO system by performing AC susceptibility ( \(\chi = \chi ' + i\chi ''\)), XRD (X Ray Diffraction) and SEM (Scanning Electron Microscopy) measurements. The Sm → Ca substitution (Bi1.6Pb0.4Sr2Ca2−xSmxCu3Oy) was carried out by conventional solid-state reaction method. The susceptibility measurements were carried out at different values of the AC field amplitudes. The imaginary part of susceptibility is used to estimate the intergranular critical current density by means of the Bean’s model. The intergranular critical current density (Jc) of pure sample is found to be about 68 A/cm2 at 95 K. The intergranular Jc is seen to decrease with increasing Sm substitution. XRD pattern and SEM micrographs are given to provide information about Bi-2223 phase and grain size respectively.