1. Institute of Electronics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee Blvd., 1784 Sofia, Bulgaria
2. CERAMATHS—Laboratoire de Matériaux Céramiques et de Mathématiques, Département Matériaux et Procédés, University Polytechnique Hauts-de-France, F-59313 Valenciennes, France
3. Institute for Nanotechnology and Correlative Microscopy eV INAM, Äußere Nürnberger Str. 62, 91301 Forchheim, Germany
4. Institute for Optics, Information and Photonics, Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Staudtstraße 7, 91058 Erlangen, Germany
5. Institute of Physical Chemistry, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Str. Bld. 11, 1113 Sofia, Bulgaria
6. G. Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, Tsarigradsko Chausse 72 Blvd, 1784 Sofia, Bulgaria
7. Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Äußere Nürnberger Str. 62, 91301 Forchheim, Germany
8. Institut für Experimentalphysik, Fachbereich Physik, Frei Universität Berlin, Arnimalle 14, 14195 Berlin, Germany
9. Faculdade de Medicina Dentária, Universidade do Porto, Rua Dr. Manuel Pereira da Silva, 4200-393 Porto, Portugal
10. LAQV/REQUIMTE, University of Porto, 4160-007 Porto, Portugal