1. Institute of Physics
2. University of São Paulo
3. São Paulo
4. Brazil
5. Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE)
6. University of Duisburg-Essen
7. 45117 Essen
8. Germany
9. Laboratório de Microscopia e Microanálises (LMM)
10. Instituto de Pesquisas Energéticas e Nucleares
11. IPEN-CNEN/SP
12. São Paulo – SP