1. Center for Technology Innovation—Materials, Research & Development Group, Hitachi, Ltd., 7-1-1 Omika, Hitachi 319-1292, Japan
2. Department of Nanomechanics, Graduate School of Engineering, Tohoku University, 6-6-1 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
3. Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1
Katahira, Aoba-ku, Sendai 980-8577, Japan
4. Institute for Materials
Research, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan