The Fe/NiO interface studied by polarization dependent X-ray absorption spectroscopy

In order to provide a structural basis for the modelling of the electronic and magnetic properties of the Fe/NiO(0 0 1) interface we have performed polarization dependent Fe K-edge X-ray absorption measurements. A multi-shell fit of the data is presented and discussed. We find that a 2 ML Fe film exhibits a complete tetragonal distortion of the unit cell and demonstrate the formation of a planar FeO layer with expanded Fe–O distances perpendicular to the growth plane. We discuss a model for the interface with the FeO layer at the oxide–metal interface. At 10 ML thickness the tetragonal strain of the Fe film is partially released.