SUPERCONDUCTING ND1.85CE0.15CUO4-Y BICRYSTAL GRAIN-BOUNDARY JOSEPHSON-JUNCTIONS

We have studied the electric transport properties of symmetrical [001] tilt Nd1.85Ce0.15CuO4-y (NCCO) bicrystal grain boundary Josephson jun ctions (GBJs) fabricated on SrTiO3 bicrystal substrates with misorient ation angles of 24 degrees and 36.8 degrees. The superconducting prope rties of the NCCO GBJs are similar to those of GBJs fabricated from th e hole doped high temperature superconductors (HTS). The critical curr ent density J(c), decreases strongly with increasing misorientation an gle. The products of the critical current I-c and the normal resistanc e R-n (similar to 100 mu V at 4.2 K) an small compared to the gap volt age and ht weIl to the universal scaling Iaw IcRn infinity root J(c) f ound for GBJs Fabricated from the hole doped HTS. This suggests that t he symmetry of the order parameter, which most likely is different for the electron and the hole doped HTS, has little influence on the char acteristic properties of symmetrical [001] tilt GBJs. (C) 1998 America n Institute of Physics.