Tuning electronic and magnetic properties of ultrathin and bulk magnetic oxides by adsorption of organic molecules

By using the Hubbard-corrected density functional theory (DFT+U ), we investigate the surface of bulk transition metal monooxides, studying the interaction with adsorbed molecules with/without intrinsic magnetic character. For the paradigmatic case of pentacene/NiO(001), we see that interaction only moderately affects the surface ground state magnetization. Conversely, ultrathin magnetic layers appear controllable by the adsorption of an organic layer, as we see by our DFT investigation for the interface formed by a C 60 molecular layer on a two-dimensional Cr 4 O 5 layer supported on Fe(001). There, the local hybridization between the electronic states of C 60 and Cr 4 O 5 is able to modify the magnetic coupling of the Cr atoms: molecules turn the ferromagnetic intra-layer coupling into an antiferromagnetic one; further patterning of the substrate spin polarization can be achieved by controlling the molecular adsorption site.