1. Faculty of Engineering of Guaratinguetá, São Paulo State University (UNESP), Guaratinguetá 12516-410, SP, Brazil
2. CDMF, LIEC, Federal University of São Carlos (UFSCar), P.O. Box 676, São Carlos 13565-905, Brazil
3. Physics Department, Federal University of São Carlos (UFSCar), P.O. Box 676, São Carlos 13565-905, Brazil
4. Department of Analytical and Physical Chemistry, University Jaume I (UJI), Castelló 12071, Spain