1. Materials Science Department, Transilvania University 1 , 500036 Brasov, Romania
2. National Institute for Lasers, Plasma and Radiation Physics 2 , 077125 Măgurele, Romania
3. Faculty of Physics, University of Bucharest 3 , 077125 Măgurele, Romania
4. Science Department, Integrated Center of Environmental Science Studies in the North-Eastern Development Region (CERNESIM), Institute of Interdisciplinary Research, Alexandru Ioan Cuza University of Iasi 4 , 700506 Iasi, Romania
5. Physics Center of Minho and Porto Universities (CF-UM-UP), University of Minho 5 , Gualtar Campus, 4710-057 Braga, Portugal
6. Department of Materials Research and Technology, Luxembourg Institute of Science and Technology (LIST) 6 , 28 avenue des Hauts-Fourneaux, Esch-sur-Alzette L-4362, Luxembourg
7. Faculty of Mechanical Engineering, Shenyang Jianzhu University 7 , 110168 Shenyang, China