Defects and Limited Power Handling Capability of YBCO Thin Films.
Abstract
We report on measurements of the microwave power dependence of the surface resistance of YBCO thin films up to very high (150 W) microwave input power levels. The experiments were carried out in a 14 GHz dielectric resonator. Frequency domain and time domain techniques were used. Limitations of the rf power handling capability caused by in-grown or irradiation-induced defects in the YBCO films were investigated. These limitations will be discussed showing a case of rf power induced step-like increase of microwave losses in one of the YBCO thin films. This increase is attributed to switching of the weak link Josephson junction in the film. Switching occurs at the rf field of 12 mT and has hysteretic behavior. Comparison of the power handling capability of irradiated and non-irradiated films will also be shown. The correlation between a defect type and rf magnetic field breakdown values will be addressed.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MAR.M3604W