Fraunhofer Institute for Ceramic Technologies and Systems IKTS
The oxygen permeability of mixed conducting membranes (MIEC - Mixed Ionic Electronic Conductor) is directly proportional to the ambipolar conductivity. Both, ionic and electronic conductivity vary significantly with temperature and oxygen partial pressure.
To characterize the high-temperature conductivity of materials, a special experimental device was built, which enables an investigation of tablet-shaped specimen with the help of van-der-Pauw method. It is possible to perform measurements up to 1050 °C using different atmospheres (O2, N2, air, gas mixtures). Highly accurate oxygen measurement and metering systems allow precise adjustment of the oxygen concentration (oxygen partial pressure) in the process gases.
These measurements are very useful to obtain important information about the conduction behavior of an investigated material, since the overall conductivity of a MIEC-material depends on the temperature and the gas composition. The results of such measurements provide an initial statements about the suitability of a material as a membrane or catalyst. In addition, the results can also be used for simulation or modeling purposes.
Services offered
- Determining the total conductivity of tablet-shaped specimens at high temperatures and different atmospheres
- temperature range of 20–1050 °C
- Measurements under different oxygen concentrations (0.1 ppm – 100% O2) and different gas atmospheres (e.g. O2, N2, Ar, CO2)
Technical equipment
- Experimental device for determining the total conductivity at high temperatures (oxygen measurement and metering systems, gas metering, temperature measuring instruments, precision current source)