10 GHz cylindrical cavity resonator for characterization of surface resistance of High T/sub c/ superconducting bulk and thin films

An accurate and simple measurement system incorporating a 10 GHz TE/sub 011/ cylindrical cavity resonator has been established which is capable of determining the microwave surface resistance of superconducting film and bulk materials of dimension independent of cavity diameter. The advantage of this technique over the conventional end plate substitution method are discussed. The performance of the cavity as a function of temperature and surface resistance measurements on YBCO thin films of 1.0 cm/spl times/0.5 cm dimension as well as 0.5 cm diameter bulk samples are presented. The lowest surface resistance measured using this system is 2.5 mohms at 77 K for a thin YBCO film deposited on LaAl/sub 2/O/sub 3/ substrate.<
>