First-principles study on the mechanical and electromagnetic properties of porous two-dimensional C7N2 crystals

Abstract

By uniformly introducing pyrazine defects on monolayer C 3 N, the porous 2D C 7 N 2 (p2D-C 7 N 2 ) crystals were obtained. Based on first-principles calculations, we systematically investigate the mechanical, electronic, and magnetic properties of p2D-C 7 N 2 crystals. The p2D-C 7 N 2 crystals have excellent performance in terms of structural and thermodynamic stability. Furthermore, we systemically study the electronic and magnetic properties of various nanoribbons by cutting from a monolayer p2D-C 7 N 2 crystals along the typical crystallographic orientations. All the nanoribbons are magnetic metals. The C 7 N 2 nanoribbons exhibit sensitive responses to edge modifications using H and O atoms. We find that the edge modifications can induce the spin semiconductor phase, non-magnetic metal phase, half-semiconductor phase, and half-metal phase. These results can open up the two-dimensional material frontier to some extent and can also provide some theoretical support for the potential application and development of nanoelectronic devices based on C 7 N 2 . • The holey 2D C 7 N 2 sheet has excellent performance in terms of structural and thermodynamic stability. • The holey 2D C 7 N 2 has the intrinsic ferromagnetic state magnetic order. • All the original C 7 N 2 nanoribbons are magnetic metals. • The edge modifications by H and O atoms in the C 7 N 2 nanoribbons can induce the different phase.