1. Department of Applied Chemistry, Chubu University, 1200 Matsumoto, Kasugai, Aichi 487-8501, Japan
2. High Pressure Group, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
3. Next-Generation Semiconductor Group, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
4. Department of Materials Science, Osaka Prefecture University, 1-1 Gakuencho, Naka-ku, Sakai, Osaka 599-8501, Japan
5. Global Center for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjukuku, Tokyo 169-8555, Japan