▎ 摘　　要

By using non-equilibrium Green's functions in combination with the density-functional theory, we investigate the spin transport properties of molecular junctions based on 3d transition terminated zigzag graphene nanoribbons. The results show that the electronic transport properties are strongly depending on the type of terminated atom at the edge of ribbon. The currents of spin-up and spin-down display different behaviors, and the spin-filter effects can be observed. These unconventional doping effects could be used to design novel nanospintronics devices. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4723832]