1. Institute of Technical Physics; Riga Technical University; Paula Valdena 3/7 1048 Riga Latvia
2. Institute of Silicate Materials; Riga Technical University; Paula Valdena 3/7 1048 Riga Latvia
3. Institute of Physics; University of Tartu; Ravila 14 c 50411 Tartu Estonia
4. RMS Foundation; Bischmattstrasse 12 P.O. Box 203 2544 Bettlach Switzerland
5. Institute of Solid State Physics; University of Latvia; Kengaraga 8 1063 Riga Latvia
6. Institute of Physics; University of Latvia; Miera 32 2169 Salaspils Latvia
7. Estonian Nanotechnology Competence Center; Ravila 14 c 50411 Tartu Estonia