1. Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan
2. Toyota Central R & D Laboratories Inc., Yokomichi, Nagakute, Aichi 480-1192, Japan
3. Kanagawa Academy of Science and Technology, Sakato 3-2-1, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan