1. Chemistry Institute, Universidade Federal do Rio Grande do Sul (UFRGS), 91501970 Porto Alegre, RS, Brazil
2. Universidade Regional Integrada do Alto Vale Uruguai e das Missões (URI), 99709-910 Erechim, RS, Brazil
3. Chemistry Department, Universidade Federal de Santa Catarina (UFSC), 88040-970 Florianópolis, SC, Brazil
4. Physics Institute, Universidade Federal do Rio Grande do Sul (UFRGS), 91501970 Porto Alegre, RS, Brazil
5. CENIMAT/i3N, Department of Materials Science, NOVA School of Science and Technology (FCT-NOVA), NOVA University Lisbon, Campus de Caparica, 2829-516 Caparica, Portugal