Geometrical structure of an iron epilayer on Si (111) : an X-ray standing wave analysis J. C. Boulliard, B. Capelle, D. Ferret, A. Lifchitz, C. Malgrange, J. F. Pétroff, A. Taccoen and Y. L. Zheng J. Phys. I France, 2 6 (1992) 1215-1232 DOI: 10.1051/jp1:1992205