Spin-polarized Dirac cones and topological nontriviality in a metal–organic framework Ni2C24S6H12

Abstract

Dirac cones in the band structure make a great contribution to the unique electronic properties of graphene. But the spin-degeneracy of Dirac cones limits the application of graphene in spintronics. Here, using first-principles calculations, we propose a two-dimensional (2D) metal–organic framework (MOF), Ni₂C₂₄S₆H₁₂, with spin-polarized Dirac cones at the six corners of the Brillouin zone (BZ). Ferromagnetism is quite stable with a high Curie temperature (630 K) as revealed by Monte Carlo simulation within the Ising model. Taking spin–orbit coupling into account, band gaps are opened up at the Dirac point (5.9 meV) and Γ point (10.4 meV) in the BZ, making Ni₂C₂₄S₆H₁₂ a Chern topological insulator which is implemented for achieving the quantum anomalous Hall effect. These interesting properties enable Ni₂C₂₄S₆H₁₂ to be a promising candidate material for spintronics device applications.