Piston-cylinder apparatus for high-pressure impedance spectroscopy

Abstract

A simple piston–cylinder apparatus was developed for impedance spectroscopy at pressures up to 3 GPa and temperatures up to 500 °C. The apparatus is of the compound cylinder type, with the innermost cylinder made of a commercially available low-cost alumina-based ceramic, with pistons of hard metal that allow electric connections. Cell electrical resistance was higher than 1 MV at T>300 °C and higher than 100 kV at 400 °C. The inductivity in the wires and pistons was about 2 mH. The sample was enclosed in a h-BN capsule, which insured a good hydrostaticity without disturbing the measurement. The equipment proved to be very useful in determining the activation volume of the conduction process in several ionic conductors.