JOURNAL OF THE KOREAN PHYSICAL SOCIETY, vol. 55, no. 1, page. 232 - 235, 2009-07
NANOTECHNOLOGY, vol. 20, no. 23, page. 1 - 6, 2009-06-10
APPLIED PHYSICS LETTERS, vol. 94, no. 17, 2009-04-27
APPLIED PHYSICS LETTERS, vol. 91, no. 22, 2007-11-26