The Ni influence on the intergranular properties of bulk (Bi, Pb): 2223 superconductor

摘要

The effect of Ni~(3+) ions on the intergranular T_p temperature of the imaginary peaks of the ac susceptibility has been studied for a (Bi, Pb):2223 superconductor. The linear dependence of T_p as a function of ac field amplitude agree with Muller critical state model. the Ni~(3+) ions induced an increase of intergranular pinning force density. J_(cJ)(T) dependence near T_c agrees with the assumption of SNS intergrain junctions.