Thermal mechanism of microwave breakdown in HTSC films: theoretical arguments and experimental evidence

Abstract

Theoretical arguments for the thermal mechanism of HTSC film microwave breakdown and their consequences are compared with experimental data. The measured values of the microwave breakdown surface magnetic field are shown to obey the temperature dependence corresponding to the thermal mechanism. The space-time pattern of the microwave breakdown seems to be related to a local overheating of the film in the vicinity of defects of size 1-10 µm. The further increase of the breakdown field may be restricted by a sharp decrease of the critical energy of external thermal disturbances initiating the microwave breakdown.