Two methods for detailed characterization of the process of oxygen exchange between the gas phase and a mixed conducting solid oxide are discussed. First, the use of solid electrolyte probes for
measuring the change in oxygen activity over the surface of a mixed conductor is presented and advantages of the technique discussed. Secondly, the use of thin film model electrodes is treated.
Studies of thin films applied by PLD on both sides of a YSZ single crystal are presented for three different film materials; La0.85Sr0.15MnO3, La0.6Sr0.4Fe0.8Co0.2O3 and La0.6Sr0.4CoO3. Variations
in electrode performance with film structure are elucidated and the rate of the exchange process on the films is compared to that observed on bulk samples.