Analyses of the electromagnetic properties of oxide superconductors by theSRPM method

Delta Z (the difference in the impedance of a solenoid coil with and withou t a superconductive sample) of 0, 10, 20 and 30wt% Ag-doped YBaCuO(c-axis o riented) and a Bi-based sintered sample were measured by the SRPM method be tween 200Hz and 1MHz at room temperature and liquid N-2 temperatures. At ro om temperature, frequency dependence of;Delta Z was observed in both sample s. These dependencies were analyzed using a serial circuit having the same resistance and inductance as the samples by which the existence of Delta Z was confirmed. Below T-c, only Delta Z of a Bi-based sample was measured be tween 200Hz and 1MHz. Delta R(the real part of Delta Z) was evaluated as a function of frequency(f). Delta R from 0.25 to 1MHz is assumed to be propor tional to f(2)(normal skin effect). Delta R from 1kHz to 50kHz is proportio nal to f(5/3) (anomalous skin effect), Delta R from 50kHz to 700kHz is prop ortional to f(2/3) (anomalous skin effect). It was found that Delta R betwe en 1kHz and 700kHz agrees with the property obtained by the equation confir ming that it is in the region of anomalous skin effect.