X-RAY SPECTROSCOPIC AND QUANTUM-CHEMICAL STUDY OF CARBON TUBES PRODUCED IN ARC-DISCHARGE

High-resolution CK alpha spectra have been obtained for samples contai ning carbon cage particles, synthesized using the ace-discharge graphi te evaporation technique. The X-ray fluorescence spectrum of particles from the inner part of the cathode deposit was found to differ from t hat of the soot collected on the chamber walls. The dependence of the spectral profile on the geometry was investigated using quantum-chemic al calculations of carbon nanotube fragments with different helical pi tches. The spectrum of multiwall particles agrees best with the theore tical spectra of zig-zag tubes. The agreement between the spectra of t ubular particles in the soot and the theoretical results is best for s ingle-wall armchair tube structures. These studies are complemented by calculations of the frontier orbitals of nanotube fragments. (C) 1998 Published by Elsevier Science B.V. AII rights reserved.