1. M. N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 18 S. Kovalevskaya Str., Yekaterinburg 620137, Russia
2. Bayerisches Geoinstitut, Universität Bayreuth, Universitätsstrasse 30, Bayreuth D-95447, Germany
3. Institute for Solid State Chemistry of Ural Branch of Russian Academy of Sciences, 91 Pervomayskaya Str., Yekaterinburg 620990, Russia