Papers Published

  1. S. Curtarolo and N. Awasthi and W. Setyawan and A. Q. Jiang and K. Bolton and T. Tokune and A. R. Harutyunyan, Influence of Mo on the Fe : Mo : C nanocatalyst thermodynamics for single-walled carbon nanotube growth, Physical Review B, vol. 78 no. 5 (August, 2008) .
    (last updated on 2009/08/04)

    We explore the role of Mo in Fe:Mo nanocatalyst thermodynamics for low-temperature chemical-vapor deposition growth of single-walled carbon nanotubes (SWCNTs). By using the size-pressure approximation and ab initio modeling, we prove that for both Fe-rich (similar to 80\% Fe or more) and Mo-rich (similar to 50\% Mo or more) Fe:Mo clusters, the presence of carbon in the cluster causes nucleation of Mo2C. This enhances the activity of the particle since it releases Fe, which is initially bound in a stable Fe:Mo phase, so that it can catalyze SWCNT growth. Furthermore, the presence of small concentrations of Mo reduces the lower size limit of low-temperature steady-state growth from similar to 0.58 nm for pure Fe particles to similar to 0.52 nm. Our ab initio-thermodynamic modeling explains experimental results and establishes a direction to search for better catalysts.