AC SUSCEPTIBILITIES IN Zn DOPED (Bi,Pb)(Sr,Ba):2223 SUPERCONDUCTOR

Abstract

AC susceptibility measurements as a function of temperature and amplitude of alternative magnetic field have been carried out on the samples (Bi,Pb)(Sr,Ba):2223 with Cu substituted by Zn at a concentration of x = 0.00, 0.02 and 0.05. The decrease of intergrain and intragrain critical temperatures with increasing x is in agreement with the increase of the residual resistivity. Using Muller critical state model and the linear dependence of Tp for the maximum of imaginary χ″(T) peak, as a function of AC field amplitude, the intergranular pining force density was obtained. The intergrain properties are more influenced than the intragrain ones.