Defects in YBCO relevant for RF superconductivity: T-, f- and H-dependencies

The present understanding of intrinsic and extrinsic HTS properties gained in the last years is applied to sintered and epitaxially grown YBCO. As results, the mean free path l increases rapidly below T/sub c/, whereas the weak links with critical Josephson current j/sub CJ/(T) and leakage current resistance R/sub bl/ describe R(T<0.8 T/sub c/, f, H) /spl cong/R/sub res/(T, f, H) over seven orders of magnitude in j/sub CJ/ with j/sub CJ/R/sub bl//sup 2//spl cong/10/sup -12/ A/spl Omega//sup 2/ cm/sup 2/.