Epitaxy and thermal behaviour of metastable metal films
Low-energy ion scattering and medium-energy electron diffraction were used to study the growth, structure and thermal stability of iron deposited on a Cu(001) surface. The system exhibits as a function of film thickness a rich variety of morphological and structural phases. At smallest coverages (<2 ML) iron does not grow layer-by-layer at room temperature. Iron is even partially incorporated into the copper substrate. Near 2 ML the substrate is covered for the most part (90 %) with Fe and at even higher coverages layer-by-layer growth occurs, leading to well-ordered fcc iron films. Above 10 ML a structural phase transition into the bcc equilibrium modification is observed. All of the deposited films exhibit additional thermal metastability. Heating the samples causes enrichment of the surface with copper, resulting in a Cu/Fe/Cu sandwich morphology with a Cu overlayer of initially monoatomic height on top of iron layers, which remain essentially intact. The onset temperature of Cu diffusion depends on the film thickness, but is always far below the values for regular bulk diffusion.
Bibliographic Reference: Article: Progress in Surface Science, Vol. 48 (1995) Nos. 1-4, pp. 275-286
Record Number: 199511194 / Last updated on: 1995-10-10
Original language: en
Available languages: en