1. Swiss Light Source, Paul Scherrer Institute, 5232 Villigen-PSI, Switzerland
2. RIKEN Spring-8 Center, Sayo, Hyogo 679-5148, Japan
3. Department of Physics, Tohoku University, Sendai, Miyagi 980-8578, Japan
4. Pi-Crystal Inc., Kashiwa, Chiba 277-0882, Japan
5. Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan