1. Department of Physics
2. Chung-Ang University
3. Seoul 06974
4. Republic of Korea
5. Institute for Materials Research
6. Tohoku University
7. Sendai 980-8577
8. Japan
9. WPI Advanced Institute for Materials Research, Tohoku University
10. Department of Electronic Materials Engineering
11. Kwangwoon University
12. Seoul 10897
13. Division of Materials Science and Engineering, Hanyang University
14. Seoul 04763