1. Department of Physics and Materials Science, University of Luxembourg, 162a avenue de la Faïencerie, Luxembourg L-1511, Luxembourg
2. CNR-NANO, Via Campi 213a, Modena 41125, Italy
3. Department of Physics & NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp B-2020, Belgium
4. Instituto de Fisica, Universidade Federal de Mato Grosso, Cuiaba, Mato Grosso 78060-900, Brazil
5. Department of Mechanical Engineering, Faculty of Engineering, Eskisehir Technical University, Eskisehir 26555, Turkey