Superconductor-normal-superconductor behavior of Josephson junctions scribed in Y1Ba2Cu3O7-d by a high-brightness electron source

We report a substantial improvement in the behavior of Josephson junctions scribed in Y1Ba2Cu3O7-? films using a high-brightness field-emission electron gun source instead of a lower-brightness thermionic source. These junctions exhibit resistively shunted junction behavior over the entire temperature range from the coupling temperature to at least 4 K, a temperature window which can be larger than 55 K. Superconductor-normal-superconductor character is indicated by the exponential dependence of the critical current on temperature for all temperatures below 90 K. The data demonstrate that electron irradiation under these conditions produces a modified region which is completely normal above 4 K and is narrower in width than previously obtained.