Accurate Measurement for Surface Resistance of a Single Piece of HTS Thin Film

An improved image type sapphire resonator was developed for accurate measurement of surface resistance of a single piece of high temperature superconductor thin film. The surface resistances of two DC spurting yttrium-barium-copper oxide (YBCO) thin films were measured by TE₀₁₁ mode of this resonator. TE₀₁₂ mode of this resonator was also used in the measurement for the determination of the frequency dependence of the surface resistance of the HTS thin film. The high accuracy in the R_s measurement of this resonator is comparable to the one of conventional two-resonator method, while the process is much simpler. The ability for measuring surface resistance of a single HTS thin film and characterizing the frequency dependence of R_s of this sapphire resonator is remarkable.