Ag-induced large perpendicular magnetic anisotropy in Mn/Ag/Fe(001)

Using the full-potential, linearized, augmented plane wave method, we have investigated the magnetic properties of body-centered-cubic Mn(2 monolayers [ML])/Fe(001), Mn(2 ML)/Ag(1 ML)/Fe(001), and Mn(2 ML)/Ag(2 ML)/Fe(001). We find that the Mn overlayers have a layered antiferromagnetic ground state. However, the Ag spacer layer induces an oscillatory magnetic behavior in Mn film, because the relative direction of magnetization in Mn film is changed with increasing Ag layer thickness. In addition, we have realized that the optimized structure is a crucial factor to determine magnetic ground state of an ultrathin Mn/Fe(001) system. It is achieved that both Mn/Fe and Mn/Ag/Fe(001) systems manifest perpendicular magnetocrystalline anisotropy (MCA). Interestingly, the Ag spacer layer greatly enhances perpendicular magnetic anisotropy energy. The MCA energy in Mn(2 ML)/Fe(001) is about 137 mu eV/cell, and it becomes 920 mu eV in Mn(2 ML)/Ag(2 ML)/Fe(001). Therefore, we report that the large perpendicular magnetic anisotropy system can be materialized in the Mn/Ag/Fe(001) structure. In addition, we also present the calculated x ray absorption spectroscopy and x ray magnetic circular dichroism of Fe and Mn layers. (C) 2011 American Institute of Physics. [doi:10.1063/1.3653836]