1. Department of Advanced Materials Science The University of Tokyo Kashiwa 277‐8561 Japan
2. Center for Emergent Matter Science RIKEN Wako 351‐0198 Japan
3. Japan Synchrotron Radiation Research Institute (JASRI) SPring‐8 Hyogo 679‐5198 Japan
4. Department of Chemistry Kindai University Osaka 577‐8502 Japan
5. Division of Materials Physics Graduate School of Engineering Science Osaka University Toyonaka Osaka 560‐8531 Japan