KINETICS OF OXYGEN INCORPORATION IN SRTIO3 (FE-DOPED) - AN OPTICAL INVESTIGATION

Due to their stability, reproducibility and fast response at elevated temperatures, SrTiO3 materials are known as powerful resistivity sensors for oxygen. Using a novel optical technique, the oxygen incorporation kinetics are investigated. At low temperature and smaller sample thicknesses, the rate-limiting step is found to be the surface process, whereas at high temperature and greater thicknesses, bulk diffusion is decisive for the response time. Bulk diffusion coefficients and surface reaction constants are discussed within a new analysis of the diffusion process, which considers trapping processes occurring in many doped and nominally pure materials.