Channel conduction mechanisms in Y–Ba–Cu–O grain boundary Josephson junctions

Abstract

Mechanisms of charge transport in high critical temperature Y–Ba–Cu–O grain boundary junctions have been analyzed in the framework of existing models. In particular, transport properties have been described by a two-channel model. Theoretical behaviors have been compared with experimental data. The scaling of the grain boundary I c GB R n GB products with the critical current density have been successfully accounted for. The performed study supports a description of grain boundaries as an array of superconductive channels, separated by non-superconductive regions, which allow the transport of quasiparticles only.