JOURNAL OF ALLOYS AND COMPOUNDS, cilt.370, ss.69-74, 2004 (SCI-Expanded)
We have carried out measurements of complex ac susceptibility x = x'+X" as a function of temperature and ac field amplitude on rectangular bar-shaped high-temperature superconductors (HTS) with nominal composition of Bi1.6Pb0.4Sr2(Ca1-xNdx)(2)Cu3Odelta superconducting samples prepared by the solid-state reaction method. The effect of Nd-substitution on the Bi-(Pb)-Sr-Ca-Cu-O system has been investigated in terms of ac susceptibility study. We estimated the effective volume fraction of the grains and the field dependence of the inter-granular critical current density comparing the maximum of the extracted matrix susceptibility and the corresponding calculated data which was obtained employing the power law critical state model. (C) 2003 Elsevier B.V. All rights reserved.