1. Institute of Thermomechanics Czech Academy of Sciences Dolejškova 5 182 00 Prague Czech Republic
2. Institute of Materials Science and Engineering Faculty of Mechanical Engineering Brno University of Technology Technická 2896/2 616 69 Brno Czech Republic
3. Faculty of Mathematics and Physics Charles University Ke Karlovu 5 121 16 Prague Czech Republic
4. FZU ‐ Institute of Physics Czech Academy of Sciences Na Slovance 1999/2 182 21 Prague Czech Republic