Fe 2 p Core-Level Spectra for Pure, Epitaxial α -Fe2O3(0001), γ -Fe2O3(001), and Fe3O4(001)

We have measured high-energy resolution Fe 2p and O 1s photoemission spectra and high-angular resolution Fe 2p and O 1s photoelectron diffraction angular distribution for the following iron oxide films grown by molecular beam epitaxy: α-Fe2O3/α-Al2O3(0001), γ-Fe2O3/MgO(001), and Fe3O4/MgO(001). The combination of these two techniques allows the crystallinographic quality of the near-surface region to be determined for each phase prior to measurement and interpretation of the core-level spectra. These spectra thus constitute state-of-the-art energy-resolved data on phase-pure, crystallographically well-defined iron oxides.