Epitaxial growth of Fe on Fe/GaAs(001) reacted layers

By using in situ techniques (RHEED, XPS and XPD), we show that the UHV annealing treatment of an epitaxial Fe/GaAs(001) structure in the 400–450°C temperature range leads to the formation of an epitaxial reacted layer. Then, we demonstrate that an epitaxial growth of Fe is possible at room temperature on such a reacted layer. As Fe is usually deposited on GaAs in the 150–200°C temperature range, this study reconciles the epitaxial growth of Fe with the interface disruption and intermixing previously observed at the beginning of the deposition.