▎ 摘 要
The spin-polarized quantum transport properties of graphene nanoribbons (GNRs) adsorbed with vanadium atoms and terminated with hydrogen are investigated by density functional theory (DFT) associated with nonequilibrium Green's function theory (NGFT). The spin current behaves nonlinearly against bias voltage for the 4-zigzag graphene nanoribbons (ZGNRs), even changing signal at certain voltages due to specific features of the coupling between molecular states and magnetic leads; For the V-adsorbed 7-armchair graphene nanoribbons (ACGNRs), the transmission coefficients is dramatical large. All these results suggest that the present structures are suitable for nanoelectronics and spintronics applications. (C) 2012 Elsevier Ltd. All rights reserved.