Comparative AC susceptibility analysis on Bi-(Pb)-Sr-Ca-Cu-O high-T-c superconductors


Celebi S.

PHYSICA C, cilt.316, ss.251-256, 1999 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

We discuss the comparative AC susceptibility analysis on rectangular bar shaped high-temperature Bi-(Pb)-Sr-Ca-Cu-O superconductors prepared by the liquid ammonium nitrate method and the solid state reaction method. Five samples used in this study were obtained from different starting compositions. The analysis for comparison is based on (i) how much rapidly the relative peak temperature (T-c - T-p) in chi "(T) increases with increasing fields; (ii) the suppression degree of the diamagnetic behavior with respect to fields; (iii) the sharpness of the transition of chi'(T) for intergranular component for the same field amplitude; (iv) the steepness of the data of chi "(T = 55 K) vs. the field amplitude. We also qualitatively discuss experimental results in the framework of the critical state model, estimate the effective volume fraction of the grains and determine the temperature dependence of the critical current density by means of the best fit of the calculated data for the experimental matrix susceptibility. (C) 1999 Published by Elsevier Science B.V. All rights reserved.