1. P.J. Šafárik University, Institute of Physics, Park Angelinum 9, 04154 Košice, Slovakia
2. Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany
3. University of Applied Sciences, Würzburger Straß e 45, 63743 Aschaffenburg, Germany
4. Deutches Elektronen-Synchrotron DESY, FS-EC, Notkestr. 85, 22603 Hamburg, Germany