The metal atomic substitution induced half-metallic properties, metallic properties and semiconducting properties in X-N 4 nanoribbons.

Armchair X-N 4 nanoribbons (X-AN 4 NRs) and zigzag X-N 4 nanoribbons (X-ZN 4 NRs) were calculated using first-principles calculations. Ferromagnets (FM) were found to be the most stable among the initial magnetic structures. Furthermore, nanoribbons were found to be thermodynamically stable through molecular dynamics simulations. It can be found that when the temperature and total energy of X-AN 4 NRs and X-ZN 4 NRs change with time, they have a small oscillation range, which confirms the dynamic stability of X-AN 4 NRs and X-ZN 4 NRs under realistic experimental conditions. Subsequently, the magnetic moment analysis of the X-AN 4 NRs and X-ZN 4 NRs revealed that the magnetic moment of the X-AN 4 NRs is significantly smaller than that of X-ZN 4 NRs. The band structure and density of states (DOS) of the X-AN 4 NRs and X-ZN 4 NRs were also computed, which indicate different properties for different transition metal nanoribbons. The results suggest that different edge structures and transition metals can influence the electronic structure of the nanoribbons. Moreover, based on the band structure and DOS, it was found that Mn-AN 4 NRs and Fe-ZN 4 NRs exhibit half-metallic properties. They can generate 100% polarized currents at the Fermi level, providing valuable information for developing spintronic devices. Our study has a positive value for regulating the properties of the nanoribbons by metal atom substitution.