Half-metallic two-dimensional polyaniline with 3d-transition-metal decoration

Abstract

Possible half-metallic behavior was explored in 3d-transition-metal (Fe, Co, and Ni) decorated two-dimensional polyaniline (C3N) on the basis of density-functional theory. 3d-transition-metal atoms would prefer to adsorb on top of the carbon hexagonal ring. The calculated electronic structures suggest the Fe and Co decorated polyanilines ((C3N)2(C3N)2<iCo) are magnetic half-metals, while the Ni-decorated polyaniline ((C3N)2<iNi) is a nonmagnetic semiconductor with an enlarged band gap. In (C3N)2<iFe, the half-metallic energy window can be as large as 0.7 eV. Interestingly, there are two half-metallic energy windows with opposite spins near Fermi level in (C3N)2<iCo. The energy windows and band gaps can be modulated by the distance between 3d-transition-metal atoms and C3N. Due to the large half-metallic energy window and the appropriate band gap, 3d-transition-metal decorated C3N may be used in nanoscale spintronic devices.