1. Deparment
of Physics, Norwegian University of Science and Technology,Høgskoleringen
5, 7491 Trondheim, Norway
2. IMMM,
UMR CNRS 6087, Université du Maine, Le Mans 72085 cedex 09, France
3. ESRF, 6 Jules Horowitz, Grenoble 38000 cedex, France
4. Université de Lorraine/CNRS, SRSMC, UMR7565, Vandoeuvre-lès-Nancy F-54506 cedex, France