Effect of interfacial Cr on magnetoelectricity of Fe2/CrO2/BaTiO3(001)

On the basis of first-principles calculations we study the effect of interfacial Cr on the magnetoelectric properties of a composite multiferroic Fe_L/BaTiO_3(001), with the Fe thickness L=1,2 monolayers. The use of the CrO_2-terminated interface instead of TiO_2 may significantly enhance magnetoelectricity in the system, showing an unexpected change in magnetization induced by the electric polarization reversal. In the case of L=2, for instance, the magnetic order of the Fe bilayer can be switched from nearly zero ferrimagnetic to ferromagnetic upon polarization reversal.