Noncollinear interface magnetism and ballistic transport inFe∕FeO∕MgO∕Fetunnel junctions:Ab initiocalculations using the KKR method

Abstract

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 $\mathrm{FeO}$ layer in the $\mathrm{Fe}∕\mathrm{FeO}∕\mathrm{MgO}∕\mathrm{Fe}$ 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-Büttiker 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%.