Unusual onset of p-element magnetization in a two dimensional structure

Based on density functional theory electronic and magnetic structure characterizations an unusual onset of spin polarization of p states is demonstrated leading to a stable ferromagnetic order within a carbon layered honeycomb-like compound. Specifically structural relaxation of formerly studied C₂N in 3D network and devised here in 2D layered AlB₂-type derived structure shows that the resulting ordered compound maintains the hexagonal crystal symmetry with an exceptionally large c/a ratio leading to strong localization of N states along c and letting magnetization develop within N-p_z orbitals with 1.1 μ_B per formula unit. Anisotropic antibonding interactions between C and N layers allow interpreting the results. The compound is energetically characterized in ferromagnetic ground state versus less stable anti-ferromagnetic order.