Surface enhanced single-molecule magnetism involving 4f spin

We study the magnetic anisotropy energy (MAE) of the isolated and deposited Eu(C8H8)2 by first-principles calculations considering the van der Waals correction and the strong correlation effects. We find that both the molecular spin moment and the easy-axis magnetic anisotropy are enhanced upon deposition on Cu(111). We propose a mechanism in terms of the weakened spin polarization of the π-2p orbitals and the induced anisotropic occupations of the 4f orbitals. Our findings pave the way for raising the MAE of 4f-element single-molecule magnets by tailoring the molecule–surface contacts.