1. CAE Team, Electric Materials Development Team, Samsung SDI Co., LTD, 428-5 Gongse-dong, Giheung-gu, Yongin-si, Gyeonggi-do, 446-577, Korea, Advanced Materials Division, Korea Research Institute of Chemical Technology, Yusung, Daejeon 305-600, Korea, and Department of Physics, Ewha Womans University, Seoul 120-750, Korea