Preparation, structure, and electronic properties ofFe3O4films on theAuthor(s) - M. Fonin, Yu. S. Dedkov, Joachim Mayer, U. Rüdiger, G. Güntherodt

The surface and interface structure as well as the electronic properties of thin epitaxial Fe 3 O 4 (111) films prepared by in situ oxidation of thin Fe(110) films grown on Al 2 O 3 (1120) substrates using a Mo(110) buffer layer were investigated by low-energy electron diffraction (LEED), scanning tunneling microscopy (STM), transmission electron microscopy (TEM), and spin-polarized angle-resolved photoemission spectroscopy (SPARPES). The annealing of Fe(110) films at 700 °C in an O 2 atmosphere leads to the formation of epitaxial Fe 3 O 4 (111) films. Atomically resolved STM images of the Fe 3 O 4 (111) surface show a hexagonal symmetry with 6 A periodicity. Well-controlled interface properties at the Fe 3 O 4 (111)/Fe(110) and Fe(110)/Mo(110) interfaces were confirmed by TEM. A high spin polarization value of about -(60′5)% was found near the Fermi energy EF at room temperature by means of SPARPES with a photon energy of hv=21.2 eV. The electronic structure and spin polarization are compared to the corresponding values recently found on epitaxial Fe 3 O 4 (111) films grown on W(110) single-crystal substrates.