R Eba Medjo et al 2009 Phys. Scr. 80 055602 doi:10.1088/0031-8949/80/05/055602
R Eba Medjo1, B Thiodjio Sendja1, J Mane Mane2,3 and P Owono Ateba1
Show affiliationsWe report a quantitative x-ray absorption spectroscopy (XAS) study of the orientation of carbon nanotubes (CNTs) grown on plain SiO2(thickness 8 nm)/Si(100) substrates by a catalytically enhanced dc hot filament chemical vapour deposition (CVD) process. The alignment and orientation of CNT films are generally provided in the literature by scanning electron microscope (SEM) and transmission electron microscope (TEM) images qualitatively. A very few other techniques have been used to more deeply study the alignment of CNTs grown by the CVD technique, such as x-ray diffraction (XRD) or grazing-incidence small-angle x-ray scattering (GISAXS). XAS recorded on the C K-edge provides information on the local environment around carbon atoms and helps us study the orientation of CNTs. We find spectral features very similar to those of HOPG, in agreement with the literature. Meanwhile, we do not observe any extinction of the π* band at grazing incidence. CNTs have an averaged direction perpendicular to the surface of the substrate.
78.70.Dm X-ray absorption spectra
81.16.Be Chemical synthesis methods
68.55.-a Thin film structure and morphology
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
Condensed matter: electrical, magnetic and optical
Issue 5 (November 2009)
Received 1 June 2009, accepted for publication 16 September 2009
Published 27 October 2009
R Eba Medjo et al 2009 Phys. Scr. 80 055602
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