1. Institute for Materials Research; Tohoku University; Sendai 980-8577 Japan
2. Japan Synchrotron Radiation Research Institute (JASRI)/SPring-8; Hyogo 679-5198 Japan
3. Department of Nanotechnology for Sustainable Energy; Kwansei Gakuin University; Hyogo 669-1337 Japan
4. Department of Electrical Engineering; Kyushu Sangyo University; Fukuoka 813-8503 Japan