Epitaxy of Fe/Cu/Si(111) ultrathin films: an Auger electron diffraction study

Epitaxial Fe films, with thickness in the range between 1 and 50 ML (monola yer, ML), were grown in ultrahigh vacuum conditions on the 7 x 7 reconstruc ted (111)-Si surface. The films were evaporated on a Cu thick buffer layer to avoid iron silicides formation. Auger electron diffraction (AED) techniq ue has been used to investigate the growth of the pseudomorphic film of fcc gamma -Fe(111) and the successive growth of bee Fe(110) domains in the Kur djumov-Sachs orientation. The early stages of growth have been carefully in vestigated through AED to assess the pseudomorphism of iron gamma -phase. A ED patterns clearly show the presence of diffraction features that are fing erprints of the existence of a few bcc arranged atomic structures even for 1 ML iron coverage. (C) 2001 Elsevier Science B.V. All rights reserved.