One-Dimensional Transition Metal-Benzene Sandwich Polymers: Possible   Ideal Conductors for Spin Transport
  We investigate the electronic and magnetic properties of the proposed one-dimensional transition metal (TM=Sc, Ti, V, Cr, and Mn)-benzene (Bz) sandwich polymers by means of density functional calculations. [V(Bz)]$_{\infty}$ is found to be a quasi-half-metallic ferromagnet and half-metallic ferromagnetism is predicted for [Mn(Bz)]$_{\infty}$. Moreover, we show that stretching the [TM(Bz)]$_{\infty}$ polymers could have dramatic effects on their electronic and magnetic properties. The elongated [V(Bz)]$_{\infty}$ displays half-metallic behavior, and [Mn(Bz)]$_{\infty}$ stretched to a certain degree becomes an antiferromagnetic insulator. The possibilities to stabilize the ferromagnetic order in [V(Bz)]$_{\infty}$ and [Mn(Bz)]$_{\infty}$ polymers at finite temperature are discussed. We suggest that the hexagonal bundles composed by these polymers might display intrachain ferromagnetic order at finite temperature by introducing interchain exchange coupling. 
H. J. Xiang, Jinlong Yang, J. G. Hou, and Qingshi Zhu