title: X-ray absorption studies of carbon-related materials.
abstract: X-ray absorption near-edge structure (XANES) measurements have been performed on nitrogen-doped diamond films with three different dopant concentrations and iron-layer-stabilized carbon nanotube (CNT) structures with various diameters at the C K-absorption edge using the sample drain current mode. The C K-edge XANES spectra of these N-doped diamond films resemble that of the undoped diamond regardless of the dopant concentration, which suggest that the overall bonding configuration of the C atom is unaltered. N dopants are found to reduce the intensities of both the sp2- and sp3-bond-derived 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 graphite sheet and the interaction between C and Fe atoms.
authors.affiliation: Department of Physics, Tamkang University, Tamsui, Taiwan. wfpong@mail.tku.edu.tw
authors.forename: W F
authors.initials: WF
authors.lastname: Pong
authors.forename: C L
authors.initials: CL
authors.lastname: Yueh
authors.forename: Y D
authors.initials: YD
authors.lastname: Chang
authors.forename: M H
authors.initials: MH
authors.lastname: Tsai
authors.forename: Y K
authors.initials: YK
authors.lastname: Chang
authors.forename: Y Y
authors.initials: YY
authors.lastname: Chen
authors.forename: J F
authors.initials: JF
authors.lastname: Lee
authors.forename: S L
authors.initials: SL
authors.lastname: Wei
authors.forename: C Y
authors.initials: CY
authors.lastname: Wen
authors.forename: L C
authors.initials: LC
authors.lastname: Chen
authors.forename: K H
authors.initials: KH
authors.lastname: Chen
authors.forename: I N
authors.initials: IN
authors.lastname: Lin
authors.forename: H F
authors.initials: HF
authors.lastname: Cheng