Formation of a body-centered-cubic Fe-based alloy at the Fe/GaAs(001) interface

摘要

The room temperature epitaxial growth of Fe films on the As-rich GaAs(001)-(2X4) surface is studied using x-ray photoelectron spectroscopy as well as reflection high-energy electron diffraction and photoelectron diffraction. Interdiffusion mechanisms take place between Fe and GaAs during the deposition of the first 4 ML (0.7 nm) Fe. The authors find that an Fe-based substitutional alloy with a body-centered-cubic structure confined on several atomic planes and containing 30% of foreign species (Ga and As atoms) sits at the Fe/GaAs(001) interface. This intermixed layer is then buried by an almost pure Fe layer.