[1] Tohoku Univ, Grad Sch Engn, Fracture & Reliabil Res Inst, Sendai, Miyagi 9808577, Japan
[2] Tohoku Univ, Inst Multidisciplinary Res Adv Mat, Sendai, Miyagi 9808577, Japan
[3] Okayama Univ, Grad Sch Nat Sci & Technol, Okayama 7008530, Japan
[4] CREST JST, Chiyoda Ku, Tokyo, Japan
[5] Waseda Univ, Dept Appl Phys, Tokyo 1698555, Japan
[6] Univ Tokyo, Inst Solid State Phys, Chiba 2778581, Japan
[7] Tokyo Inst Technol, Dept Organ & Polymer Mat, Tokyo 1528550, Japan