The electronic band structure of $\sqrt{3}\times \sqrt{3}R30\mathrm{}°\epsilon$-FeSi(111) epitaxially grown on Si(111) has been probed by angle-resolved polarization-sensitive ultraviolet photoemission in the energy range 8 eV $<~h\nu <~$ 30 eV. The bands were mapped along the $\Gamma \mathrm{R}$ direction of the Brillouin zone for different detection geometries. A comparison with theoretical calculations reveals a good agreement of the overall features at room temperature. A sharp peak close to the Fermi energy was observed. Its origin is discussed taking into account both conventional and Kondo-insulator models currently considered to explain the properties of $\epsilon$-FeSi.

• Received 22 May 1997

DOI:https://doi.org/10.1103/PhysRevB.57.1414