Low ac field response of Bi-based superconductors with addition of Antimony oxide

We report the effects of the addition of Sb2O3 on the superconducting properties of Bi-2223 system. Samples with composition Bi1.7Pb0.3Ca2Sr2Cu3SbxOy (x=0,0-0.8 wt.%) are prepared by the solid-state reaction method. Ac susceptibility and high harmonic response of polycrystalline superconductors are measured in weak ac and dc magnetic fields. Critical state models are used to explain the nonlinear magnetic response and it is found that the low field odd harmonic response is qualitatively explained reasonably well within the Kim-Anderson regime. We observed that, the low level Antimony doping enhances the transport critical current densities Jc.