Electronic structure of the Fe3O4(111) surface -: art. no. 073405

The surface electronic band structure of thin, well-ordered epitaxial Fe3O4(111) films has been investigated at room temperature by means of angle-resolved photoelectron spectroscopy using synchrotron radiation. In the (Gamma) over bar-(M) over bar direction of the Fe3O4(111) surface Brillouin zone (SBZ), two types of dispersion states originating from a periodic multilayered structure of iron and oxygen ions, in which Fe2+ and Fe3+ cations are incorporated into the close-packed fcc oxygen sublattice, were identified. Oxygen 2p-derived states at binding energies between 2.5 and 8 eV follow a strong, monotonic dispersion extending from (Gamma) over bar to (M) over bar of the oxygen-sublattice originating SBZ. On the other hand, the iron 3d-derived states near the Fermi energy show a weak dispersion with a period half of the ($) over bar Gamma-(M) over bar distance of the latter. The surface electronic band structure of the Fe3O4(111) film measured with photoemission is described as composed from matrix-element governed contributions of the oxygen and the iron sublattices which are related to the different symmetries of their SBZs.