1. High Field Magnet Laboratory (HFML-EMFL), Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
2. Radboud University, Institute for Molecules and Materials, 6525 AJ Nijmegen, The Netherlands
3. Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, D-01187 Dresden, Germany