1. National Center for Materials Study and Testing, Technical University of Moldova; 2004 Chisinau Republic of Moldova
2. Functional Nanomaterials; Institute for Materials Science, Christian Albrechts University of Kiel; 24143 Kiel Germany
3. H.H. Wills Physics Laboratory; University of Bristol; BS8 1TL Bristol UK
4. Department of Physics; University of Central Florida; Orlando FL 32816-2385 USA
5. Institute of Electronic Engineering and Nanotechnologies, Academy of Sciences of Moldova; 2028 Chisinau Republic of Moldova