1. Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
2. Institut Laue-Langevin, F-38042 Grenoble Cedex 9, France
3. Department
of Physics and Chemistry, University of Southern Denmark, Campusvej
55, 5230 Odense
M, Denmark
4. School of Conservation, The Royal Academy of Fine Arts Schools of Architecture, Design and Conservation, Esplanaden
34, DK-1263 Copenhagen, Denmark
5. Laboratoire National des Champs Magnétiques
Intenses, CNRS, BP 166, F-38042 Grenoble Cedex 9, France