Ferromagnetism and perfect spin filtering in transition-metal-doped graphyne nanoribbons

Ferromagnetism in half-metallic two-dimensional materials can lead to unique spintronics applications. Here we report first-principles calculations that predict monolayer graphyne nanoribbons (GyNRs), an alternative to graphene, doped randomly with 3d-series transition metal atoms at medium-to-high concentrations (2%-5%) can be ferromagnetic (FM). Furthermore, Mn- and Co-doped GyNRs are half-metallic with 100% spin polarization at the Fermi level and can act as perfect spin filters. The high spin polarization of the current is preserved up to large bias voltages. This study provides a basis for the fabrication of GyNRs with ferromagnetism and spin-polarized electron transport properties.