X-ray absorption studies of carbon-related materials

X-ray absorption near-edge structure (XANES) measurements have been perform ed on nitrogen-doped diamond films with three different dopant concentratio ns and iron-layer-stabilized carbon nanotube (CNT) structures with various diameters at the C K-absorption edge using the sample drain current mode. T he C K-edge XANES spectra of these N-doped diamond films resemble that of t he undoped diamond regardless of the dopant concentration, which suggest th at the overall bonding configuration of the C atom is unaltered. N dopants are found to reduce the intensities of both the sp(2)- and sp(3)-bond-deriv ed resonance features in the XANES spectra. On the other hand, the C K-edge XANES spectra of CNTs indicate that the intensities of the pi* and sigma* bands and the interlayer-state features vary with the diameter of the CNT. This phenomenon may be caused by the Fe-layer-catalysed bending of the grap hite sheet and the interaction between C and Fe atoms.