Properties of trilayer SIS junctions with YBa/sub 2/Cu/sub 3/O/sub 7-y/

In this study, we compared the surface configurations of PrGaO/sub 3/ (PGO) and multilayers of PGO and CeO/sub 2/ deposited on YBa/sub 2/Cu/sub 3/O/sub 7-y/ (YBCO) thin films. It is found that the multilayers have flatter surfaces than single layers of the same thickness. Furthermore, the voltage-current characteristics of sandwich type SIS junctions with a range of single barrier and double barrier thickness using YBCO electrodes were investigated. Double layer barriers are effective in suppressing electrical short circuits caused by pinholes. The junction with a double barrier of 5 nm PGO and 2.5 nm CeO/sub 2/ shows a Josephson current.