Defect Chemistry
The ionic point defects are the decisive ionic carriers in solids comparable to H+ and OH- in water or electrons and holes in semiconductors (see figures below). Their concentration and mobilities determine electrical and chemical transport properties as well as the kinetics of solid state reactions. For dilute defects, their concentrations can be quantitatively described by mass action laws.

formation of point defects from J. Maier (1993)

defects as acid-base active centers from J. Maier (2001)
Research areas:
Establishing of defect models (defect concentrations in dependence of control parameters such as temperature, partial pressures, doping concentrations, etc.)
- Defect-defect interactions
- Defect chemistry in boundary regions
- Defect chemistry in frozen-in situations
Survey papers:
- J. Maier: Defect Chemistry: Composition, Transport, and Reactions in the Solid State; Part I: Thermodynamics, Angewandte Chemie International Edition 32(3), 313–335 (1993). DOI: 10.1002/anie.199303133
- J. Maier: Acid-Base Centers and Acid-Base Scales in Ionic Solids Chemistry — A European Journal 7(22), 4762–4770 (2001). DOI: 10.1002/1521-3765(20011119)7:22<4762::aid-chem4762>3.0.CO;2-F
- J. Maier: Solid State Electrochemistry I: Thermodynamics and Kinetics of Charge Carriers in Solids, Modern Aspects of Electrochemistry, B. E. Conway, C. G. Vayenas, and R. E. White, eds., number 38, Kluwer Academic/Plenum Publishers, New York, 2005, pages 1–173. DOI: 10.1007/b106562
- J. Maier: Solid State Electrochemistry II: Devices and Techniques, Modern Aspects of Electrochemistry, C. G. Vayenas, R. E. White, and M. E. Gamboa-Adelco, eds., number 41, Springer, New York, 2007, pages 1–138. DOI: 10.1007/978-0-387-46108-3
Current Projects:
- Size effects in nanocrystalline SrTiO3
- Interface effects in superconducting heterostructures
- defect thermodynamics and kinetics
- Concentration and mobility of protons in H+-SOFC cathode materials
- Defect chemistry of the LiFePO4/FePO4 redox couple
- Li storage in TiO2: defect chemistry
- Defect chemistry of alkali peroxides
- The influence of ion-pair transport in salt containing liquid electrolytes
- Interfacial storage : Defect chemistry of interfacial storage
- Stable proton conducting oxides for high drain electrochemical applications
- Formation and migration of carriers in phosphoric acid and related systems
- Ion transport and photo-induced phase instability in mixed halide perovskites
- Nanoionics of hybrid perovskite interfaces
- Ionics of layered 2D perovskites
- Optoionics of hybrid perovskites topics