1. Faculty of Engineering, Tohoku Gakuin University, 1-13-1 Chuo, Tagajo, Miyagi 985-8537, Japan
2. Daido Steel Co., Ltd., 11-18, Nishiki 1-chome Naka-ku, Nagoya Aichi 460, Japan
3. Research Institute for Electromagnetic Materials, 2-1-1, Yagiyama-minami, Taihaku-ku, Sendai 982-0807, Japan