SUPERCONDUCTOR SCIENCE & TECHNOLOGY, cilt.9, sa.6, ss.467-473, 1996 (SCI-Expanded)
The magnetic response of Bi-based superconductors of nominal composition Bi1.8Pb0.2Sr2Ca3Cu4O12 against low AC field amplitudes is studied in terms of fundamental and third harmonic AC susceptibilities to investigate various physical parameters. Optimum conditions of a wet preparation technique have been determined. Both transport and inductive critical current densities have increased considerably on samples subjected to a single intermediate grinding. The magnetic data accompanied by XRD measurements support the theory that the minor superconducting phase 2212 is mostly screened by a dominating matrix of 2223 high-T-c phase.