LOW-FIELD DIAMAGNETIC RESPONSE OF GRANULAR SUPERCONDUCTORS AT FINITE TEMPERATURES

We study the low-field diamagnetic response of granular superconductor s at finite temperatures by means of a simple two-dimensional Josephso n-junction array. The temperature effects are taken into account by in serting white-noise current sources in parallel to the resistively shu nted junction circuit models of the Josephson junctions of the network . By this analysis we argue that a simplified one-dimensional descript ion of the equivalent circuit, proposed by the authors for cylindrical granular superconductors, is still valid even in the presence of ther mally activated flux jumps. A flux-creep picture for intergranular flu x motion follows.