AC 4-PROBE IMPEDANCE MEASUREMENTS ON SOLID ELECTROLYTES WITH HIGH IMPEDANCE

An a.c. four-probe setup was built to measure impedance spectra betwee n 1 Hz and 100 kHz on solid electrolytes up to impedance values of 10 G Ohm. A solution to minimize the source of errors by means of preampl ifiers for current and voltage signals is presented. A special constru ction of the sample holder is necessary to give the best results in co njunction with the preamplifiers. The holder is designed for measureme nts on solid electrolytes in a wide temperature range. The performance of the setup and the residual error sources are determined. Measureme nts of the four-probe impedance spectra on yttria stabilized zirconia in the temperature range between room temperature and 750 degrees C ar e given as an example.