Spatially resolved measurements of the microwave surface resistance of HTS thin films with a dielectric resonator design at 10.5 GHz and 77 K

We have developed and applied a method to measure the surface resistance of HTS films spatially resolved. To avoid high characterizing frequencies and to get an enhanced frequency stability we used a special parallel-plate resonator design. The system uses a stationary dielectric puck system and moves the HTS thin film sample over the open resonator, sampling the surface resistance at a frequency of 10.5 GHz. The spatial resolution of the prototype system is 9 mm. An adjustable coupling allows to measure the surface resistance in-situ as a function of the strength of the microwave magnetic field. We describe measurements of the spatial variation of linear and nonlinear effects in the surface resistance of YBa₂Cu₃O₇ films at 77 K