Low field AC magnetic susceptibility measurement in Pb-doped Bi-2223

Abstract

AC Susceptibility measurements at very low field were done on a polycrystalline Pb-doped Bi-2223. A Hartshorn-type mutual inductance bridge set-up was used to measure the field and frequency-dependence of the inter- and intragranular components of susceptibility. Interestingly, aside from the usual two-step superconductive transition observed from different high-Tc superconductors, a third step-wise transition is seen at various fields on both χ' and χ" of this sample. This feature is attributed to the presence of Bi-2212 phase belonging to the BSCCO family with a lower transition temperature.