Chemical structure of the interface between MgO films and Fe(001)

Abstract

The chemical structure of the interface formed during MgO growth on Fe(001) is studied by vibration spectroscopy employing a high resolution electron energy loss spectrometer. We find direct, spectroscopic evidence for the formation of FeO layer at the interface that is triggered by the dissociation of oxygen molecule by deposited Mg. Even though the growth conditions of MgO are widely varied, FeO cannot be eradicated at the interface. Hence, we propose that the phase where FeO and MgO coexist at the interface, is an entropically stabilized one in regards to the very small difference between the bond dissociation energy of FeO and that of MgO. (C) 2003 American Institute of Physics.