Josephson junctions and SQUIDs based on artificial grain-boundaries in Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}-thin films

High quality thin films of Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} with critical temperatures of 95 K were used to prepare grain boundary Josephson Junctions on commercial 36.8{degree} SrTiO{sub 3}-bicrystal substrates. I{sub c}R{sub n}-products of 50 {micro}V at 77 K and 0.7 mV at 4.2 K have been reached. For temperatures higher than 50 K the current-voltage curves of the junctions can be well described by the resistively shunted junction (RSJ) model and show no hysteresis. From the hysteretic behavior at low temperature the authors estimate a junction capacitance of 21 {micro}F/cm{sup 2}. The Fraunhofer pattern of the critical current in an external applied field shows, that the junctions are inhomogeneous on a {micro}m scale. The SQUID modulation of a 30 x 40 {micro}m{sup 2} wide superconducting loop containing two 10 {micro}m wide junctions yields a flux-voltage transfer function of 2.7 {micro}V/{Phi}{sub 0} at 78 K.