1. Faculty of Physics and EngineeringNational Research Tomsk State University Tomsk 634050 Russia
2. Institute of Strength Physics and Materials ScienceRussian Academy of Sciences Siberian Branch Tomsk 634055 Russia
3. Physics FacultySouthern Federal University ul. Zorge 5 Rostov-on-Don 344090 Russia
4. Department of PhysicsInstitute of Materials ScienceUniversity of Connecticut Storrs CT 06269-3046 USA
5. Faculty of BuildingTomsk State University of Architecture and Building Tomsk 634003 Russia