Comunicazione

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

Fratesi G., Achilli S., Orlando F., Marino M., Molteni E., Onida G.
  Martedì 13/09   09:00 - 13:30   Aula D - Marianna Ciccone   II - Fisica della materia   Presentazione
The surface of a magnetic material plays an important role in defining the electronic and magnetic properties of hybrid organic-inorganic interfaces for application in spintronic devices. We present first-principles density functional theory (DFT) methods to investigate the interface formed by a $C_{60}$ molecular layer on a Fe(001) surface covered by a two-dimensional $Cr_{4}O_{5}$ layer showing that the latter enhances the induced magnetic moment on the molecules by a slower decay of the spin polarization in vacuum with respect to the pristine surface. We also show that the local hybridization between the electronic states of the $Cr_{4}O_{5}$ layer and those of the organic molecules 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 adsorption site. We then investigate by Hubbard-corrected ${DFT}+U$ calculations the surface of bulk transition metal monooxides and their electronic and magnetic properties in the near surface region, studying the interaction with adsorbed molecules with/without intrinsic magnetic character.