Electronic characterization of single walled carbon nanotubes: a Xanes study

The electronic structure of two different samples of single wall carbon nanotubes (SWCNs) have been investigated using X-ray absorption near edge spectroscopy (XANES). The XANES data, detected around the C K edge, have been compared with that of a pure HOPG sample used as structural standard. The measurements have been carried out at the photoemission 4B9B beamline (Synchrotron Radiation Facility of the Institute of High Energy Physics of Beijing) using a surfacesensitive total electron yield technique. The samples were previously characterized usingRamanspectroscopy, electron microscopy (SEM), and tunneling microscopy (STM). The bonding properties of C atoms ( * and * bands of sp2–coordination) and the structural characteristics are identified by looking at the changes in both pre-edge and multiple-scattering regions of the XANES spectra