1. Department
of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University, Aramaki,
Aoba, Sendai, 980-8578, Japan
2. Department
of Materials Science and Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan
3. Department
of Physics, Graduate School of Science, Nagoya University, Japan, Furo-cho,
Chikusa, Nagoya 464-860, Japan