Investigations for the Existence of an Iron-Oxide Layer at the MgO/Fe Interface

We have investigated the possibility of an interface between MgO and Fe lms to explore the existence of an oxide layer at the MgO/Fe interface as a preliminary system of Fe/MgO/Fe magnetic tunnel junctions. By using photoemission spectroscopy and X-ray absorption spectroscopy, we found that no iron-oxide layer existed at the interface for the in-situ-grown epitaxial MgO(001)/Fe(001) bilayer on a W(001) substrate. Moreover, we showed that metal Mg could revivify the iron-oxide to metal Fe when MgO was formed. These results show we can make iron-oxide-free samples in the Mg-rich growth condition.