We have fabricated YBa/sub 2/Cu/sub 3/O/sub 7/ ramp-type junctions incorporating a barrier layer of NdGaO/sub 3/ with a nominal thickness of 2 nm. The junctions exhibit pronounced Josephson effects and operate up to 82 K. The characteristics are well described within the resistively shunted junction model. We observe large hysteresis parameters /spl beta//sub c/ even at elevated temperatures. The output voltage of a high-T/sub c/ dc SQUID is found to benefit from the intrinsic junction capacitance.
Camille Sophie Brès, Marco Clementi, Jiaye Wu, Qian Li, Xuanyi Liu