▎ 摘　　要

A pristine zigzag-edge trigonal graphene (ZTG) is a magnetic semiconductor, thus its spin polarization is extremely low. Here, we report the calculated results on enhancing the spin magnetism of a zigzag-edge trigonal graphene (ZTG) by functionalizations, including the heteroatom doping, edge modifications, and introducing topologic defects. It is found that the ZTG features a good tuning ability for functionalizations to improve its spin polarization. When one boron (B) atom is doped to replace one carbon atom in the B sublattice of graphene, a higher spin polarization can be achieved, and the edge modification by Cu, Co, O or B atom can modulate the magnetic ordering significantly due to the spin-polarized charge transfer between the ZTG and terminations, especially for O and Co terminations. And also, the introduced defect (a vacancy and a Stone-Wales defect) can obviously tune local magnetic structures owing to geometrically structural deformations (variations of bond length and bond angle). For these behaviors, in-depth analyses are performed. Our findings suggest that the desirable functionalized ZTG structures might promise importantly potential applications for developing nano-scale spintronics devices. (C) 2014 Elsevier B.V. All rights reserved.