Residual surface resistance of YBa/sub 2/Cu/sub 3/O/sub x/ thin films-weakly coupled grain model

The residual surface resistance and the magnetic penetration depth of high-T/sub c/ superconducting YBa/sub 2/Cu/sub 3/O/sub x/ thin films have been measured using the coplanar waveguide resonator technique, and are discussed with the weakly coupled grain model, where the superconducting polycrystalline thin film is described as a network of superconducting grains coupled via Josephson junctions. The observed dependence of the residual resistance and the magnetic penetration depth on the critical current density and the grain size is shown to demonstrate the weakly coupled grain model of YBa/sub 2/Cu/sub 3/O/sub x/ thin films.