Features of the microwave breakdown of a high-Tc superconducting film at defects

The influence of nonsuperconducting defects on the power density for microwave breakdown of a high-T-c superconducting film is investigated theoretically. It is found that the scenario of the destruction of superconductivity depends substantially on the shape of the defect and on the ratio of the absorption coefficients of the defect and film. It is shown that the breakdown power density at a defect may be higher than or equal to the threshold power density for microwave breakdown of a homogeneous film. (C) 1998 American Institute of Physics.