The local structure of hydrogen storage nanocrystalline graphite by neutron scattering

The total and inelastic neutron scattering measurements were employed in order to get more information on the local structure of nanocrystalline graphite prepared by mechanical milling under D-2 gas atmosphere. In the RDF(r) for the sample after 50 h of milling, newly grown peak around 0.154 nm was found at the larger r side of the first nearest peak corresponding to the C-C correlation. The distance 0.154 nm of the C-C correlation is attributed to 4-fold bonding. Moreover, the inelastic neutron scattering peak observed in the 160-190 meV region for the samples after 20 h of milling indicates new emergence of sp(3) bonding. The results apparently indicate that terminating D atoms at the edges of the nano-lattice plane of graphite create the new sp(3) bonding of C atoms during the milling process under D, gas atmosphere. (C) 2002 Elsevier B.V. All rights reserved.