Manipulating Magnetism at Organic/Ferromagnetic Interfaces by Molecule-Induced Surface Reconstruction.

Fullerenes have several advantages as potential materials for organic spintronics. Through a theoretical first-principles study, we report that fullerene C60 adsorption can induce a magnetic reconstruction in a Ni(111) surface and expose the merits of the reconstructed C60/Ni(111) spinterface for molecular spintronics applications. Surface reconstruction drastically modifies the magnetic properties at both sides of the C60/Ni interface. Three outstanding properties of the reconstructed structure are revealed, which originate from reconstruction enhanced spin-split π-d coupling between C60 and Ni(111): (1) the C60 spin polarization and conductance around the Fermi level are enhanced simultaneously, which can be important for read-head sensor miniaturization; (2) localized spin-polarized states appear in C60 with a spin-filter functionality; and (3) magnetocrystalline anisotropic energy and exchange coupling in the outermost Ni layer are reduced enormously. Surface reconstruction can be realized simply by controlling the annealing temperature in experiments.