Spin-resolved photoemission studies of epitaxial Fe3O4(100) thin films

In situ spin-resolved photoemission studies have been performed on expitaxial Fe 3 O 4 thin films grown on MgO(1 0 0). The spin polarization of the valence band at the Fermi level has been found to be -55.5% and not -100% as predicted by the first-principles calculations. Our spin-resolved measurements provide direct experimental evidence showing that Fe 3 O 4 is not a half-metal as a result of electron-electron correlation effects, and that Fe 3 O 4 should be considered as a strongly correlated system.