1. Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
2. Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia
3. Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu, Estonia
4. Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia
5. Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, IW3, 28359 Bremen, Germany