1. Department
of Materials Science and Engineering, Chonnam National University, 300 Yongbong-dong, Bukgu, Gwangju 500-757, Republic of Korea
2. Beamline Research
Division, Pohang Accelerator Laboratory, Pohang 790-784, Republic of Korea
3. Department
of Applied Chemical Engineering, Chonnam National University, 300 Yongbong-dong, Bukgu, Gwangju 500-757, Republic of Korea