1. Hitachi Research
Laboratory, Hitachi, Ltd., 7-1-1 Omika-cho, Hitachi 319-1292, Japan
2. Fracture
and Reliability Research Institute, Graduate School of Engineering, Tohoku University, 6-6-11 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
3. WPI
Advanced Institute for Materials Research, Tohoku University, 2-1-1
Katahira, Aoba-ku, Sendai 980-8577, Japan
4. Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University 2-1-1
Katahira, Aoba-ku, Sendai 980-8577, Japan