Electron-correlation-induced magnetic order of ultrathin Mn films

We studied the electronic and magnetic properties of ultrathin Mn films deposited onto Cu, Ni, and Fe surfaces with x-ray-absorption and resonant-photoemission spectroscopies. The observed strong changes in the Mn 2p branching ratio as a function of coverage and substrate type indicate a change from localized to itinerant behavior. The 2p3p3p resonant photoemission triplet state shows two features which can be assigned to a well-screened and a poorly screened final state. The intensity ratio between these two states allows corroboration of the electron localization. Magnetic circular x-ray dichroism gives the spin magnetic moment of the Mn ground state and information about the Mn-substrate magnetic coupling. Combining these results we propose a simple explanation for the magnetic behavior of the Mn layers.