1. Laboratoire de Physique des Solides, CNRS
UMR 8502, Université Paris Sud XI, 91405 Orsay, France
2. Synchrotron-SOLEIL, BP 48, Saint-Aubin, F91192 Gif sur
Yvette CEDEX, France
3. Department of Physics, University of California Davis, Davis, California 95616, United States
4. Materials
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
5. Peter Grünberg Institut PGI-6, Forschungszentrum
Jülich, 52425 Jülich, Germany
6. Department of Physics
and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala, Sweden
7. Institut Laue-Langevin, 38000 Grenoble, France
8. Unité Mixte de Physique CNRS/Thales,1 Avenue A. Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
9. National Institute of Advanced Industrial Science and Technology (AIST), JST, PRESTO, Tsukuba, Ibaraki 305-8562, Japan