To avoid effects caused by quenching and/or incomplete freezing-in of defect chemical reactions, in-situ spectroscopic methods (elevated T, adjusted component activity (pO2, pH2O etc)) are preferable. Spectroscopic methods with spatial resolution for investigation of transport processes are also in the focus.
Research areas and related projects:
- Space resolved optical spectroscopy -> kinetics of stoichiometry change
Denk, F. Noll, and J. Maier: In-situ Profiles of Oxygen Diffusion in SrTiO3: Bulk Behavior and Boundary Effects Journal of the American Ceramic Society 80(2), 279–285 (1997). DOI:10.1111/j.1151-2916.1997.tb02827.x
- Nuclear magnetic resonance -> proton transport in polymers
M. Schuster, T. Rager, A. Noda, K. D. Kreuer, and J. Maier: About the Choice of the Protogenic Group in PEM Separator Materials for Intermediate Temperature, Low Humidity Operation: A Critical Comparison of Sulfonic Acid, Phosphonic Acid and Imidazole Functionalized Model Compounds
Fuel Cells 5(3), 355–365 (2005). DOI: 10.1002/fuce.200400059
- Electron paramagnetic resonance -> in-situ measurement of defect concentrations
R. Merkle and J. Maier: Defect association in acceptor-doped SrTiO3: case study for FeTi'VO .. and MnTi''VO ..
Physical Chemistry Chemical Physics 5(11), 2297–2303 (2003).
- Oxygen isotope exchange/SIMS -> diffusion / surface reaction kinetics
M. Leonhardt, R. A. De Souza, J. Claus, and J. Maier: Surface Kinetics of Oxygen Incorporation into SrTiO3 Journal of The Electrochemical Society 149(2), J19–J26 (2002). DOI: 10.1149/1.1430723
- X-ray absorption spectroscopy -> local structure information
M. Vracar, A. Kuzmin, R. Merkle, J. Purans, E. A. Kotomin, J. Maier, and O. Mathon
Jahn-Teller distortion around Fe4+ in Sr(FexTi1-x)O3-δ from x-ray absorption spectroscopy, x-ray diffraction, and vibrational spectroscopy Physical Review B 76(17), 174107 (1–12) (2007). DOI:10.1103/PhysRevB.76.174107