First-Principles Calculations of Magnetism in Nanoscale Carbon Materials Confining Metal with f Valence Electrons

Abstract

The f electrons in the unfilled shell of actinide and lanthanide display complex bonding behavior and the hybridized sp electrons in carbon could show spin polarization in finite nanostructures. Correspondingly, materials combining these two features exhibit abundant magnetic properties. In this paper, we outline our first-principles calculations on various nanoscale carbon materials confining U and Gd which are representative actinide and lanthanide, respectively. The complex interaction between f electrons and sp electrons make the induced magnetic property sensitive to metal specie and carbon confinement. Specially, (1) The magnetism could be suppressed by stronger adsorption with vacancy sites on graphene and adjusted by varying the valence state of some endohedral metallofullerenes (EMFs). (2) The magnetic coupling between metal and carbon structures could be promoted by large curvature when confinement site is carbon nanotubes and altered by the adatom defect on fullerene cages. (3) Untrivial magnetic property with large net spin and asymmetric spin distribution is obtained by confining U atom and Gd atom in one fullerene as a heteronuclear EMF. These results contribute to a systematic understanding of the magnetism in nanoscale carbon materials confining metal with f valence electrons.