Angle-resolved photoemission study of a thin FeO(111) layer formed on Fe(110)

The electronic properties of a thin FeO(111) layer epitaxially grown on Fe(110) have been studied by angle-resolved photoemission spectroscopy using polarized synchrotron radiation. The normal-emission spectra show five features: Fe 3d–derived states at ∼0.4 and 2.7 eV below the Fermi energy, O 2p–derived states at ∼4.1 and ∼6.0 eV, and a multielectron satellite feature at 11.5 eV. The binding energies of these states were independent of hν within ±0.05 eV, in accord with the two- dimensionality of the layer. The band structure was mapped out in the two symmetry directions of the surface Brillouin zone: FeO[112¯] (Γ¯M¯) and FeO[11¯0] (Γ¯K¯). The Fe 3d–derived states show little dispersion (≲0.2 eV) with ${\mathrm{k}}_{?}$, while the O 2p–derived states exhibit considerable dispersion of ∼2–3 eV in both directions. The dispersion of the O 2p– derived bands can be understood in terms of a simple tight-binding model.