Simulation of the intergranular magnetization of (Bi,Pb)(2)Sr2Ca2Cu3O10+x superconductors by using Josephson junction arrays

In this paper we present a numerical simulation study of the intergranular magnetization of (Bi,Pb)(2)Sr2Ca2Cu3O10+x superconductors. The intergranular-current system was modelled as a two-dimensional Josephson junction array, which consists of superconducting grains connected via overdamped, narrow Josephson weak links. The simulations cover magnetic-flux distribution and magnetic-hysteresis studies, including relaxation effects due to thermal fluctuations in the junctions. Special attention was paid to the influence of intergranular defects on the array magnetization and intergranular (Bi,Pb)(2)Sr2Ca2Cu3O10+x. A correspondence with the experimental results [Paasi et al., Physica C 259(1996) 1) (previous paper)] required that there was an intergranular defect of the mu m order located in the middle of the four grains of an array mesh. Such a defect could act as a strong pinning center for intergranular flux.