1. Institute of Experimental Physics, Faculty of Physics, University of Warsaw, L. Pasteura 5, PL-02093 Warszawa, Poland
2. Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA-EMFL, 25, av. des Martyrs, 38042 Grenoble, France
3. National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan