1. Department
of Applied Physics, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628, Japan
2. Department
of Chemistry, Faculty of Science, Hokkaido University, Kita 10 Nishi
8, Kita-ku, Sapporo 060-0810, Japan
3. Materials
and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan