Noncollinear interface magnetism and ballistic transport in Fe/FeO/MgO/Fe tunnel junctions: Ab initio calculations using the KKR method

On the basis of ab initio total energy calculations made with the screened Korringa-Kohn-Rostoker method we discuss the possibility of the formation of noncollinear magnetic structures near the FeO layer in the Fe/FeO/MgO/Fe tunnel junction. It was shown that the competition between the intrinsic antiferromagnetism of iron oxide and ferromagnetism of pure iron can result in the stabilization of a tilted noncollinear configuration at the interface. We used the Landauer-Buttiker approach modified for noncollinear magnetic structures in order to calculate the ballistic conductance of the junction in the tunneling regime. The conductance has a nonsinusoidal orientation dependence and varies by a maximum of 200%.