Magnetic and Electronic Properties of Samarium-Doped Phenanthrene from First-Principles Study

Based on the van der Waals density functional theory (DFT), we have studied the crystal structure and magnetic and electronic properties of samarium-doped phenanthrene, a newly discovered aromatic superconductor. For Sm(i)phenanthrene, we found that the magnetism in the ground state is antiferromagnetic, in good agreement with the experimental measurement. When Hubbard U of 6 eV is considered, the Sm-1-A structure becomes an atomic force microscopy (AFM) semiconductor with a gap of 0.12 eV. Including the spin orbit coupling, the orbital moment of the Sm atom is 2.28 mu(B) with the opposite direction to the spin moment of 5.99 mu(B). The total moment of 3.7 mu(B) around Sm atoms in Sm-doped phenanthrene is quite distinct to the divalent and trivalent Sm ions in monochalcogenides and samarium hexaboride. The hybridization of Sm 5d and C 2d states results in a relatively strong interaction of metal and molecule in Sm-doped phenanthrene compared with the interaction in K-doped picene and phenanthrene. Our results provide the fundemental magnetism and electronic properties of the Sm-doped phenanthrene superconductor.