Applied Physics Letters, vol. 87, no. 12, 2005-09-19
Applied Physics Letters, vol. 85, no. 15, page. 3235 - 3237, 2004-10-11
Thin Solid Films, vol. 441, no. 1-2, page. 317 - 320, 2003-09-22
Physical Review B, vol. 67, no. 23, 2003-06-15