APPLIED SURFACE SCIENCE, vol. 221, no. 1-4, page. 231 - 236, 2004-01-15
JOURNAL OF MATERIALS RESEARCH, vol. 14, no. 4, page. 1658 - 1663, 1999-04
JOURNAL OF APPLIED PHYSICS, vol. 80, no. 5, page. 2791 - 2798, 1996-09-01