1. Federal Institute of Education, Science and Technology of Ceará, PPGET, Ceará, Fortaleza-CE, Brazil;
2. Department of Physics, Telecommunications and Materials Science and Engineering Laboratory (LOCEM), Federal University of Ceará, Caixa, Fortaleza-CE, Brazil;
3. Department of Physics, University of Aveiro, Aveiro, Portugal
4. Department of Physics and Chemistry, São Paulo State University, Ilha Solteira, SP, Brazil;