1. Laboratorio
de Magnetismo y Nanotecnología, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain
2. Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
3. Physical
Chemistry Department, University of Vigo, E-36310 Vigo, Spain
4. INL - International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal