TRANSPORT-PROPERTIES IN TL-BA-CA-CU-O GRAIN-BOUNDARY JUNCTIONS ON SRTIO3 BICRYSTAL SUBSTRATES

We have investigated the electrical properties of TI-Ba-Ca-Cu-O high-T (c) superconductor bicrystal grain boundary junctions. The behavior of the transport parameters is very similar to those obtained in YBaCuO7 -delta junctions. In particular, the temperature dependence of the cri tical current and the scaling behavior of the critical current density as a function of the misorientation angle were analyzed. Relatively g ood control of the transport parameters as a function of the misorient ation angle has been achieved. The current-voltage characteristics sho wed a resistively shunted junction model-like behavior at large angles (theta greater-than-or-equal-to 20-degrees); at lower angles, the cha racteristics were more flux-flow like. Preliminary results on noise ch aracteristics are also presented.