PHYSICAL REVIEW B, vol. 62, no. 5, page. 3025 - 3028, 2000-08-01
MATERIALS LETTERS, vol. 43, no. 5-6, page. 225 - 229, 2000-05
JOURNAL OF APPLIED PHYSICS, vol. 87, no. 9, page. 4205 - 4209, 2000-05-01
JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 36, no. 1, page. 54 - 59, 2000-01