magnetic alignment of TM adatoms adsorbed on the GY, especially their magnetic exchange coupling mediated by the *sp* hybridized carbon atoms.\
One dimensional (1D) TM monoatomic chain, whose magnetic properties are much different from those of bulk solid materials because of significant reduction in dimensionality, shows potential applications in spintronic devices, such as spin-dependent quantum transport properties, ballistic anomalous magnetoresistance,[@57] spin and magnetization tunneling[@58]. Moreover, much researches[@52; @59; @60] have shown that the 1D TM metallic chain can lead to large magnetic anisotropy. In present work, using density functional theory plus Hubbard-U (DFT+U) approach we find that the TM adatoms on GY can be constructed as TM chain indicating that the GY is a potential template for synthesizing TM nanowire. Such TM chain can behave as a metallic nanowire with spin-polarized currents or quantum channel bringing a new opportunity to construct integrated circuits using various combinations of connected monoatomic metallic wire based on GY. Moreover, such monoatomic TM chains can be created on the surface of GY by STM tip manipulation[@29; @30; @31; @32; @33; @34]. In view of the strong intermediate of *sp* hybridized carbon atom, it is easy to retain a long range magnetic order on the surface 