FIELD PERCOLATION AND HIGH-CURRENT DENSITY IN 80 20-DYBA2CU3O7-X/DY2BACUO5 BULK MAGNETICALLY TEXTURED COMPOSITE CERAMICS/

We measured the AC susceptibility of magnetically textured (123) 80%/2 11(20%) DyBaCuO composite in a special set-up in order to enhance the intergrain contribution. The synthesis process led to very clean ''wea k links'' at grain boundaries. At the percolation threshold bulk shiel ding paths were such that the intergrain critical current density J(c) was above 10(5) A/cm(2). The field dependence of J(c) was understood through an analytical form indicating a distribution of currents simil ar to the law of clusters at fracture/percolation thresholds.