1. Brazilian Nanotechnology National Laboratory (LNNano), National Center for Research in Energy and Materials (CNPEM), 13083-100 Campinas, São Paulo, Brazil
2. Department of Physical Chemistry, Institute of Chemistry, University of Campinas, UNICAMP, 13084-862 Campinas, Brazil
3. Institute of Physics ″Gleb Wataghin″ (IFGW), University of Campinas, UNICAMP, 13083-859 Campinas, Brazil
4. Centre of Natural and Human Sciences, Federal University of ABC, Santo André, São Paulo 09210-580, Brazil