Low-field AC susceptibility study of critical current density in Eu:123 and Bi:2223 superconductors

Abstract

Low-field AC susceptibility measurements have been made, at different values of AC field amplitude H m (26–600 A/m), on Eu:123 and Bi:2223 samples. Analysis of the temperature dependence of the AC susceptibility has been done employing Beans’ critical state model. The intergranular critical current density ( J c) is calculated as a function of both H m and temperature for both samples, respectively. It is found that J c increases with increasing H m for both samples and its values are generally higher in Bi sample than in Eu sample. Our results are discussed in terms of zero-temperature pinning potential βI(0) in both systems.