▎ 摘　　要

Here, we demonstrate chemical synthesis of graphene based nano-spin valve like structures using nickel layers as ferromagnetic contacts grown on both sides of graphene sheets. Magnetic measurements indicate that the spins on two opposite nickel layers are coupled through antiferromagnetic interaction up to room temperature. However, they switch into parallel configuration when a magnetic field of about 2000 Oe is applied resulting in a change in magnetoresistance of similar to 19%.