The effect of paramagnetic impurities in normal metal on the critical current in a network of S N S Josephson junctions in bulk Y_3/4Lu_1/4Ba₂Cu₃O₇  BaPb_1 xFe_xO₃composites

Abstract

composites representing a model of a network of superconductor-normal metal-superconductor (SNS) Josephson junctions with paramagnetic impurities (Fe) in the N layers have been prepared. The transport properties of the composites have been studied. An exponential decay of the critical current with increasing Fe content in the non-superconducting ingredient of the composite has been observed. Such a behaviour is accounted for in terms of the de Gennes proximity effect theory.