In situ x-ray diffraction study of epitaxial growth of ordered Fe3Si films

TL;DR

This study uses in situ grazing incidence x-ray diffraction to analyze the layer-by-layer epitaxial growth and surface evolution of Fe3Si films on GaAs(001), revealing growth dynamics, surface roughening, and recovery processes.

Contribution

It provides detailed in situ insights into the epitaxial growth mechanism, surface roughening, and post-deposition surface recovery of Fe3Si films, which were not previously characterized in real-time.

Findings

Layer-by-layer growth observed at low rates and 200°C.

Surface roughening causes damping of x-ray oscillations.

Annealing with Fe3Si deposition restores surface quality.

Abstract

Molecular beam epitaxy of Fe3Si on GaAs(001) is studied in situ by grazing incidence x-ray diffraction. Layer-by-layer growth of Fe3Si films is observed at a low growth rate and substrate temperatures near 200 degrees Celsius. A damping of x-ray intensity oscillations due to a gradual surface roughening during growth is found. The corresponding sequence of coverages of the different terrace levels is obtained. The after-deposition surface recovery is very slow. Annealing at 310 degrees Celsius combined with the deposition of one monolayer of Fe3Si restores the surface to high perfection and minimal roughness. Our stoichiometric films possess long-range order and a high quality heteroepitaxial interface.