1. Department of Materials Science and Technology; Nagaoka University of Technology; 1603-1, Kamitomioka Nagaoka Niigata 940-2188 Japan
2. School of Polymer Science and Engineering; Chonnam National University; 77 Yongbong-ro Buk-gu Gwangju 500-757 Korea
3. Research Center for Exotic Nanocarbons (JST); Shinshu University; 4-17-1 Wakasato Nagano 380-853 Japan
4. Department of Physics; Department of Materials Science and Engineering & Materials Research Institute; The Pennsylvania State University; 104 Davey Lab., University Park PA 16802-6300 USA
5. Faculty of Engineering; Shinshu University; Wakasato 4-17-1 Nagano 380-8553 Japan