MORPHOLOGICAL AND COMPOSITIONAL STUDY AT THE Si/Fe INTERFACE OF (Fe/Si) MULTILAYER

Abstract

Diffusion and reaction of elements at the interfaces of nanostructured systems play an important role in controlling their physical and chemical properties for subsequent applications. ( Fe / Si ) nanolayers were prepared by thermal evaporation under ultrahigh vacuum onto a Si (100) substrate. A morphological characterization of these films was performed by combination of scanning transmission electron microscopy (STEM) and X-ray reflectivity (XRR). The compositional depth profile of the ( Fe / Si ) structures was obtained by angle resolved X-ray photoelectron spectroscopy (ARXPS) and hard X-ray photoelectron spectroscopy (HAXPES). Moreover, determination of the stable phases formed at the Si on Fe interfaces was performed using conversion electron Mössbauer spectroscopy. The Si / Fe interface thickness and roughness were determined to be 1.4 nm and 0.6 nm, respectively. A large fraction of the interface is composed of c- Fe 1-x Si paramagnetic phase, though a minoritary ferromagnetic Fe rich silicide phase is also present.