title: Increasing the efficiency of single walled carbon nanotube amplification by Fe-Co catalysts through the optimization of CH4/H2 partial pressures.
abstract: Single walled carbon nanotubes (SWNTs) seeds are grown using Fe-Co nanoparticles on spin-on-glass. The relative efficiency of nucleation and amplification (versus etching) was investigated as a function of the CH(4)/H(2) feedstock ratio and growth temperature. At 900 °C, maximum amplification is obtained with CH(4)/H(2) ratio of 80:20 but 60:40 for nucleation. Amplification is further enhanced at 800 °C, compared with etching dominating at 1000 °C. Amplification of SWNTs is in equilibrium with etching; higher carbon feedstock pressure and decreased temperature increase the rate of amplification; the converse increases etching.
authors.affiliation: Richard E. Smalley Institute for Nanoscale Science and Technology, Department of Chemistry, Rice University, Houston, Texas 77005, United States.
authors.forename: Alvin W
authors.initials: AW
authors.lastname: Orbaek
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Owens
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Barron
mesh_terms: D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008697:Methane / Q000737:chemistry*; D036103:Nanotechnology; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010316:Particle Size; D011312:Pressure; D013499:Surface Properties; D013696:Temperature
chemical_list: D037742:Nanotubes, Carbon; D003035:Cobalt; D006859:Hydrogen; D007501:Iron; D008697:Methane