1. a Group of Applied Optics, Faculty of Science and Technology , Federal University of Grande Dourados, Dourados-Itahum Road, Km 12 , Dourados , MS , Brazil , 79804-970, P.O. Box 533
2. b Group of Ferroelectric Ceramics, Department of Physics, Federal University of Sao Carlos , Washington Luiz Road, km 235 , Sao Carlos , SP , Brazil , 13565-905
3. c Multifunctional Electronic Materials and Devices Laboratory, Department of Electrical & Computer Engineering , University of Texas at San Antonio, One UTSA Circle , San Antonio , Texas , 78249-0669 , USA