1. Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502
2. Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502
3. Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044
4. Superconducting Materials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044