1. Universidade Federal de Santa Maria
2. Department of Chemistry
3. Laboratory of Inorganic Materials
4. 97105-900 Santa Maria
5. Brazil
6. Freie Universität Berlin
7. Institute of Chemistry and Biochemistry
8. D-14195 Berlin
9. Germany
10. Department of Physics
11. Helmholtz-Zentrum Dresden-Rossendorf
12. Institut für Ressourcenökologie
13. 01314 Dresden