1. Czech Academy of Science, Prague Institute of Physics, , Na Slovance 1999/2, Praha 8 182 21 , Czech Republic
2. University of Chemistry and Technology Prague Department of Metals and Corrosion Engineering, Faculty of Chemical Technology, , Technická 5, Praha 6—Dejvice 166 28 , Czech Republic
3. Slovak Academy of Science Institute of Materials and Machine Mechanics SAS, , Dubravska Cesta 9, Bratislava 84513 , Slovakia