respectively). Moreover, the adsorption energy per TM adatom for V-dimer-GY and Fe-dimer-GY systems is more stable than corresponding single V and Fe adsorption systems(the adsorption energy for single TM adsorbed GY system is -1.672, -1.331, -1.433, -2.424, and -2.541eV for V, Cr, Mn, Fe, and Co, respectively). Such stability is derived from the existence of -C$\equiv$C- bond. The $p_x$ and $p_y$ of *sp*-hybridized carbon atoms in the GY contribute to both $\sigma$-bond and $\pi$-bond, making it easily to couple with the TM adatom. Increasing the number of TM atoms, we find that the adsorption energy is similar with the dimer configuration. Therefore, it is expected that a regular TM nanowire with a single atom thickness is possible to be constructed in the surface of GY sheet. Our results demonstrate that GY sheet are promising template for TM nanowire in spintronics.\
After achieving the TM dimer adsorption configuration, we investigate the TM chains adsorbed on surface of GY. In present work, we consider TM (V, Cr, Mn, Fe and Co) zigzag monoatomic chain as shown in Fig.\[fig1\]. The adsorption energies and structure parameters of equilibrium TM-chain-GY are listed in Tab.\[tab1\]. The considerable negative adsorption energies for all of the 3d TM-chain 