Title :
Analyses of the electromagnetic properties of oxide superconductors by the SRPM method
Author :
Miyairi, H. ; Kodaira, T. ; Yamazaki, S. ; Nakane, H. ; Haseyama, S. ; Kohayashi, S.
Author_Institution :
Dept. of Electr. Eng., Kogakuin Univ., Tokyo, Japan
fDate :
6/1/1999 12:00:00 AM
Abstract :
/spl Delta/Z (the difference in the impedance of a solenoid coil with and without a superconductive sample) of 0, 10, 20 and 30 wt% Ag-doped YBaCuO (c-axis oriented) and a Bi-based sintered sample were measured by the SRPM method between 200 Hz and 1 MHz at room temperature and liquid N/sub 2/ temperatures. At room temperature, frequency dependence of /spl Delta/Z was observed in both samples. These dependencies were analyzed using a serial circuit having the same resistance and inductance as the samples by which the existence of /spl Delta/Z was confirmed. Below T/sub c/, only /spl Delta/Z of a Bi-based sample was measured between 200 Hz and 1 MHz. /spl Delta/R (the real part of /spl Delta/Z) was evaluated as a function of frequency(f). /spl Delta/R from 0.25 to 1 kHz is assumed to be proportional to f/sup 2/ (normal skin effect). /spl Delta/R from 1 kHz to 50 kHz is proportional to f/sup 5/3/ (anomalous skin effect). /spl Delta/R from 50 kHz to 700 kHz is proportional to f/sup 2/3/ (anomalous skin effect). It was found that /spl Delta/R between 1 kHz and 700 kHz agrees with the property obtained by the equation confirming that it is in the region of anomalous skin effect.
Keywords :
anomalous skin effect; barium compounds; bismuth compounds; calcium compounds; electrical resistivity; high-temperature superconductors; lead compounds; penetration depth (superconductivity); silver; strontium compounds; yttrium compounds; 200 Hz to 1 MHz; 293 K; 77 K; BiPbSrCaCuO; SRPM; YBaCuO:Ag; anomalous skin effect; frequency dependence; impedance; inductance; magnetic penetration depth; normal skin effect; oxide superconductors; resistivity; Electrical resistance measurement; Electromagnetic analysis; Electromagnetic measurements; Impedance measurement; Skin effect; Solenoids; Superconducting coils; Superconductivity; Temperature; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on