1. Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 180 40 Praha 8, Czech Republic
2. Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic
3. Institute for Technical Electrochemistry, Technical University of Vienna, Getreidemarkt 9, 1060 Vienna, Austria