1. Materials Science and Engineering Department; Technical University of Cluj-Napoca; 103-105 Muncii Avenue Cluj-Napoca 400641 Romania
2. Institut Néel; CNRS and Université Joseph Fourier; 25 rue des Martyrs Grenoble 38042 France
3. Physics and Chemistry Department; Technical University of Cluj-Napoca; 103-105 Muncii Avenue Cluj-Napoca 400641 Romania