1. Department of Materials and Environmental Chemistry, Stockholm University, SE-106
91 Stockholm, Sweden
2. Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, D-01328 Dresden, Germany
3. Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
4. Max Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany