1. Graduate School of Engineering, Osaka University, 2-1 Yamada-oka Suita, 565-0871, Japan
2. Nippon Steel Chemical Co., Ltd., 46-80, Nakabaru Sakinohama, Tobata-Ku, Kitakyushu, Fukuoka 804-8503, Japan
3. Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
4. Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-12 Ookayama, Meguro, Tokyo 152-8552, Japan