1. Institute
for Materials Research, Tohoku University, Sendai, Miyagi 980-8577, Japan
2. Department
of Materials Science and Engineering, Kyoto University, Kyoto 606-8501, Japan
3. Yokohama R&D Laboratories, Furukawa Electric Co., Ltd., Yokohama, Kanagawa 220-0073, Japan
4. Metal
Research Center, Furukawa Electric Co., Ltd., Nikko, Tochigi 321-1493, Japan