Metal Oxide Film for Growing Vertically Aligned Single-Walled Carbon Nanotubes

In the present study, we use a method that uses the oxidation state of platinum in Co-Cr-Pt oxide films to cause a volume expansion to form isolated nanoparticles through exposure to H-2 microwave plasma. The generated nanoparticles are then used to grow single-walled carbon nanotubes (SWCNTs) at similar to 600 degrees C without the application of a buffer layer using a microwave plasma chemical vapor deposition system. The effects of metal oxide film thickness on the growth of SWCNTs are investigated. The characterization techniques including X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy are carried out, with the results showing that this method used is highly efficient in generating very small and dense catalytic nanoparticles. The results also show that, when the metal oxide film thickness is no more than 2nm, the nanoparticles produced with diameters ranging from 2 to 3nm can be effective for growing vertically and densely aligned SWCNTs. (C) 2009 The Japan Society of Applied Physics