1. Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland
2. Div. of Information and Communication Sciences, Macquarie Univ., Sydney, Australia
3. Microstructural Analysis Unit, UTS, Sydney, Australia
4. Dept. of Physics and Materials Sciences Center, Phillips-University of Marburg, Renthof 5, 35032 Marburg, Germany