Magnetism at metal-ceramic interfaces: effects of a Au overlayer on the magnetic properties of Fe/MgO(001)

In the search for a benign magnetic substrate with which to explore 2D magnetism in transition metal monolayer, MgO(001) has emerged from studies of the metal-ceramic interface as a prime candidate. Since Au overlayers are now used to prevent oxidation, we have determined their effects on the electronic and magnetic properties of Fe/MgO(001) by means of first principles calculations using the full potential linearized augmented plane wave method. Some Fe-Au hybridization is found which diminishes the giant spin moment in Fe/MgO(001) by 0.14μ_B. In turn, the Fe layer induces a sizable magnetic moment at the Au site, namely, a 0.069μ_B spin moment and a 0.042μ_B orbital moment. A substantial magnetic circular dichroism signal is predicted for Au, which invites experimental verification.