AC four-probe impedance measurements on solid electrolytes with high impedance

An a.c. four-probe setup was built to measure impedance spectra between 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 preamplifiers for current and voltage signals is presented. A special construction of the sample holder is necessary to give the best results in conjunction with the preamplifiers. The holder is designed for measurements on solid electrolytes in a wide temperature range. The performance of the setup and the residual error sources are determined. Measurements of the four-probe impedance spectra on yttria stabilized zirconia in the temperature range between room temperature and 750 degrees C are given as an example.