Affiliation: | a Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstrasse 8-10, A-1040 Vienna, Austria b Department of Inorganic Chemistry, Ivan Franko National University of Lviv, Kyryla and Mefodia Str. 6, UA-79005 Lviv, Ukraine c H.V. Karpenko Physico-Mechanical Institute, National Academy of Science of Ukraine, Naukova Str. 5, UA-79601 Lviv, Ukraine |