▎ 摘　　要

We propose that charge injection can be used to tune the magnetic anisotropy of transition metal monolayer adsorbed on graphene substrate. Using relativistic density-functional calculations, we calculate magnetocrystalline anisotropy energy (MAE) of freestanding Fe monolayer and Fe/graphene complex system. We find MAE of Fe atom is drastically changed, from meV/atom in freestanding Fe monolayer to mu eV/atom in Fe/graphene system. The more interesting finding is, through charge injection, the suppressed MAE of Fe atoms in Fe/graphene system can be restored back, which provides an effective approach to control MAE. We expect such strategy would be beneficial to graphene based spintronic devices. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3697627]