FT-ICR studies of laser vaporized clusters from Ni/Co- and Ni/Y-loaded graphite samples

Metal-carbon binary clusters generated by the laser vaporization of Ni/Co- and Ni/Y-loaded graphite samples used for the macroscopic production of SWNTs were studied. Positive and negative clusters generated by the laser-vaporization supersonic-expansion cluster beam source were directly injected into the FT-ICR mass spectrometer. The chemical reaction of these clusters with NO was used as the probe of the geometrical structure of clusters. It was speculated that a few Ni or Co atoms attached outside of imperfect carbon cage for Ni/Co loaded case, and that Y atom was included in the carbon cage for Ni/Y loaded case. (C) 2002 Elsevier Science B.V. All rights reserved.