[1] Nano-Surface Analysis Team, Korea Basic Science Institute, Busan 609-735, Korea, Republic of
[2] Sch. of Nano-Science and Technology, Pusan National University, Busan 609-735, Korea, Republic of
[3] Department of Materials Engineering, Chungnam National University, Daeduk Science Town, Daejon 305-764, Korea, Republic of
[4] Electronic Ceramics Center (ECC), Dept. of Info. Materials Engineering, Dong-Eui University, Busan 614-714, Korea, Republic of