1. Brazilian
Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-970 Campinas, São Paulo, Brazil
2. Institute
of Physics “Gleb Wataghin” (IFGW), University of Campinas (UNICAMP), 13083-859 Campinas, São
Paulo, Brazil
3. Department
of Physical Chemistry, Institute of Chemistry (IQ), University of Campinas (UNICAMP), 13084-862 Campinas, São
Paulo, Brazil