▎ 摘　　要

We study the effects of metallic doping on the electronic properties of graphene using density functional theory in the local density approximation in the presence of a local charging energy. The electronic properties are sensitive to whether graphene is doped with alkali or transition metals. We estimate the charge transfer from a single layer of potassium on top of graphene in terms of the local charging energy of the graphene sheet. The coating of graphene with a nonmagnetic layer of palladium, on the other hand, can lead to a magnetic instability in coated graphene due to the hybridization between the transition metal and the carbon orbitals.