▎ 摘　　要

The magnetic property and band structures of Co-monolayer doped graphene were examined on the basis of density-functional theory. The magnetic moment of the system is closely related to the interfacial spacing. Magnetic-nonmagnetic transition would be produced by decreasing the layer distance. Although the magnetic moment can also be reduced by increasing the lattice constant, the ground states are magnetic states under tension. Besides, the increase of lattice constant greatly enlarges the direct and indirect gaps of spin-down bands near the Fermi level. With a little increase of the Fermi level or the electron density, half-metal behavior would be expectable in the Co-doped graphene under tension. (C) 2015 AIP Publishing LLC.