Theoretical study of the termination of the Fe3O4 (111) surface

摘要: Abstract Ab-initio periodic Hartree–Fock calculations for the structure of (111) surface Fe3O4 (magnetite) are presented. The slabs that derived by an ideal bulk truncation leaves one or two iron monolayers outside oxygen layers found to be more stable than others since they preserve most coordination atoms. stability represent depends on overall composition, specifically deviation from stoichiometry, and dipole moment perpendicular surface. symmetrical slab with layer sequence Fe2O4Fe3O4Fe2, terminated each side bilayers, is best compromise symmetry insures neutrality moment. This oxygen-deficient. energetically preferred relaxes so outermost moves toward center plane, exchanging layer. FeO4Fe3O4Fe, which also symmetric, single monolayers, would excessive oxidation may reduced hydrogenation; it then strongly stabilized vertical displacement atoms agrees determined LEED (the study not have detected hydrogen).