NEXAFS detection of graphitic layers formed in the process of carbon nanotube arrays synthesis

Angle-resolved near-edge X-ray absorption fine structure (NEXAFS) method has been applied for revealing graphitic layers distribution in the samples of aligned multi-walled carbon nanotubes (CNTs) synthesized by aerosol-assistant catalytic chemical vapor deposition (CCVD) technique. The arrays of CNTs were produced on silicon substrates for different times of the reaction mixture injection. The NEXAFS spectra of the samples showed the opposite behavior of π* resonance depending on the incidence angle of the exciting beam. The behavior for the sample grown during short time (5 min) was found to be characteristic of disordered graphite. Based on the scanning electron microscopy images we suggested the mechanism for formation of graphitic layers perpendicular to the direction of CNT growth.