1. Department of Physics, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560
2. Fukui National College of Technology, Sabae, Fukui 916-8507
3. Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa, Yamagata 990-8560