1. Laboratory for Advanced Materials, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 84215Bratislava, Slovakia
2. Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 84536Bratislava, Slovakia
3. Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 84104Bratislava, Slovakia
4. Centre for Nanodiagnostics of Materials, Faculty of Materials Science and Technology, Slovak University of Technology, Vazovova 5, 81243Bratislava, Slovakia