An in-situ study of structure and magnetic properties of Fe films on the sulphur passivated Ge(100) surface at 150°C

Ultra-thin Fe films have been grown on the sulphur passivated Ge(100) surface at 150 degrees C. The growth, structure and the magnetic properties of the thin films were studied with LEED, AES, angle resolved AES and in-situ magnetooptical Kerr effect measurements. For the first five monolayers of Fe, no long-range order was observed. However, angle resolved AES data suggest that local order occurs with a small fraction of the Fe atoms adsorbed on bcc sites. For thicker Fe films, the growth becomes ordered. A comparison of the present study and with a previous study of the growth of Fe on sputter cleaned Ge(100) (2 x 1) surface, shows that sulphur passivation effectively prevents Fe-Ge intermixing. During the Fe deposition process, most of the sulphur atoms migrate to the growing surface, thus acting as surfactants. The presence of sulphur at the surface also affects the growth and magnetic properties of the thin films. (C) 1999 Elsevier Science B.V. All rights reserved.