Towards the quantitative theory of the high-T/sub c/ Josephson junctions

The possible reasons leading to the reduction of the characteristic voltage V/sub C/ of the high-temperature-superconductor (HTS) Josephson Junctions are discussed. It is emphasized that the electron scattering at the superconductor-normal-metal (SN) boundaries plays a decisive role in HTS weak links. Rough estimates of the parameter gamma /sub B/ describing the SN boundary transparency were obtained. Calculations of the properties of the SNS sandwiches, variable thickness bridges, and SNIS' tunnel junctions within the framework of BCS-based theories of the Josephson effect have been carried out using models which take into account the low transparency of HTS/N-metal interfaces, and possible values of their I/sub c/R/sub N/ product are estimated.