Study of Nd substitution in Bi-(Pb)-Sr-Ca-Cu-O high-Tc superconductors

Measurements of complex AC susceptibility chi = chi' + chi" as a function of temperature and AC field amplitude have been carried out on rectangular bar-shaped high-temperature superconductors 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 an AC susceptibility study. It was found that as the amount of Nd content x increases, the transition temperature decreases. Temperature-dependent critical current density was deduced from AC susceptibility data. In spite of a slight decrease of T-c, the highest pinning strength parameters (J(cm) (T=0) and temperature exponent n) were obtained for the sample with x=0.02. (C) 2002 Elsevier Science B.V. All rights reserved.