1. High
Field Magnet Laboratory, Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 7, NL-6525 ED Nijmegen, The Netherlands
2. LNF-INFN and CNR-IFN, Via E. Fermi 40, 00044 Frascati, Italy
3. INSTM Udr
Trieste-ST
and Sincrotrone Trieste, Area Science
Park, I-34012 Trieste, Italy
4. Department
of Physics and Astronomy Rutgers, The State University of New Jersey 136 Frelinghuysen Road Piscataway, New Jersey 08854-8019, United States