Formation of Epitaxial CsCl-Type Iron Silicide on Si(111)

Abstract
The epitaxial growth of a cubic Fe silicide phase on Si(111) has been confirmed by means of X-ray photoelectron diffraction (XPD) and surface-extended X-ray absorption fine-structure (SEXAFS) experiments. XPD experiments show that a 5-monolayer Fe film deposited on Si(111) and subsequently annealed at ~ 500 °C has a cubic structure. SEXAFS measured at the Fe K edge (7110 eV) reveals that Fe atoms are coordinated with eight Si atoms with bond length of (2.38 ± 0.04) Å and with six Fe atoms with bond length of (2.71 ± 0.04) Å. All measurements lead to the conclusion that this cubic silicide has a CsCl-type structure.