Electronic structure and magnetism of samarium and neodymium adatoms on free-standing graphene

• Published in: Physical review. B 2016-09, Vol.94 (12), p.125113, Article 125113
• Main Authors: Kozub, Agnieszka L., Shick, Alexander B., Máca, František, Kolorenč, Jindřich, Lichtenstein, Alexander I.
• Format: Article
• Language: English
• Subjects: Adatoms; Cures; Density functional theory; Electron spin; Electronic structure; Electrons; Graphene; Magnetic moments; Magnetic properties; Magnetism; Neodymium; Rare earth elements; Samarium; Spin-orbit interactions
• ISSN: 2469-9950; 2469-9969
• DOI: 10.1103/PhysRevB.94.125113

The electronic structure of selected rare-earth atoms adsorbed on a free-standing graphene was investigated using methods beyond the conventional density functional theory (DFT+U, DFT+HIA, and DFT+ED). The influence of the electron correlations and the spin-orbit coupling on the magnetic properties has been examined. The DFT+U method predicts both atoms to carry local magnetic moments (spin and orbital) contrary to a nonmagnetic f6 (J = 0) ground-state configuration of Sm in the gas phase. Application of DFT+Hubbard-I (HIA) and DFT+exact diagonalization (ED) methods cures this problem, and yields a nonmagnetic ground state with six f electrons and J = 0 for the Sm adatom. Our calculations show that Nd adatom remains magnetic, with four localized f electrons and J = 4.0. These conclusions could be verified by STM and XAS experiments.