1. Department of Physics, Graduate School of Science, Kyoto Sangyo University, Kyoto 603-8555, Japan
2. Superconductivity Research Laboratory, International Superconductivity Technology Center, Koto, Tokyo 135-0062, Japan
3. Osaka Prefecture University, Sakai 599-8531, Japan
4. Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan
5. Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan