1. Department of Experimental Physics Faculty of Fundamental Problems of Technology Wroclaw University of Science and Technology Wybrzeze Wyspianskiego 27 50-370 Wroclaw Poland
2. Institute of Physics Faculty of Materials Engineering and Technical Physics Poznan University of Technology Piotrowo 3 60-965 Poznan Poland
3. Electron Microscopy Laboratory Faculty of Mechanical Engineering Wroclaw University of Science and Technology Wybrzeze Wyspianskiego 27 50-370 Wroclaw Poland