Fe/NiO(100) and Fe/MgO(100) interfaces studied by X-rayabsorption spectroscopy and non-linear Kerr effect

Abstract

A structural characterization of the Fe/NiO(100) and Fe/MgO(100)interfaces is reported. Polarization-dependent X-ray absorptionspectroscopy has been employed to explore the local atomicstructure of the interfaces. A strong difference between the twosystems is observed: the Fe/MgO(100) interface does not showa significant Fe oxidation or oxygen diffusion while a buckledFeO like layer is observed at Fe/NiO(001). Moreover, while on theMgO(001) substrate the tetragonal strain is released at 10 ML Fethickness, a residual epitaxial strain can be observed on a film ofthe same thickness on NiO(001). A magnetic characterization of theFe/NiO(001) system by linear and non-linear magneto-optical Kerreffect measurements is also reported and discussed.' 2009 Elsevier Ltd. All rights reserved