1. Departamento de Física y Matemáticas Universidad Autónoma de Manizales Antigua Estación del Ferrocarril Manizales CP 170001 Colombia
2. Institute of Technology in Polymers and Nanotechnology - ITPN UBA-CONICET FIUBA FADU University of Buenos Aires Intendente Güiraldes s/n, Pabellón III, Ciudad Universitaria (C1428EGA) Buenos Aries Argentina
3. Department of Physics and Astronomy University of Texas at San Antonio One UTSA Circle San Antonio TX 78249 USA
4. Faculty of Engineering Institute of Technology and Engineering Sciences “Hilario Fernández Long” (INTECIN-CONICET) University of Buenos Aires Paseo Colón 850 Buenos Aires C1063ACV Argentina
5. Applied Physics and Materials Science Department and Materials Interfaces Research and Applications (MIRA) Northern Arizona University Flagstaff 86011 USA
6. Instituto de Fisica 'Gleb Wataghin’ (IFGW) Universidade Estadual de Campinas 13083-970 Campinas SP Brazil