1. Institute
of Physics, Academy of Sciences of the Czech Republic, Na Slovance
2, 182 21 Prague, Czech Republic
2. Centro de Ciências e Tecnologias
Nucleares, Instituto Superior Técnico, Universidade de Lisboa, P-2695-066 Bobadela, Portugal
3. Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden, Germany
4. Institut des Sciences Chimiques de Rennes, Chimie du
Solide et Matériaux, Université Rennes 1, UMR CNRS 6226, 263 Avenue du Général Leclerc, 35042 Rennes, France
5. Department of Condensed Matter Physics, Faculty of Mathematics and
Physics, Charles University, Ke Karlovu 5, 121 16 Prague, Czech Republic