1. i3N and Physics Department of University of Aveiro, 3810-193 Aveiro, Portugal
2. CICECO and Physics Department of University of Aveiro, 3810-193 Aveiro, Portugal
3. Materials Metrology
Division, INMETRO, 25250-020, Duque de Caxias - RJ, Brazil
4. CICECO and Dept. of Materials and Ceramic
Engineering, University of Aveiro, 3810-193 Aveiro, Portugal