H_2 Dissociative Adsorption at the Armchair Edges of Graphite

We investigate and discuss how hydrogen behaves at the edges of a graphite sheet, in particular the armchair edge. Our density functional theory-based calculations results show that, in contrast to the zigzag edge [cf., e-J. Surf. Sci. Nanotech. 2 (2004) 77], regardless of orientation, there is an activation barrier hindering H_2 dissociation at the armchair edges. And once they do get dissociatively adsorbed at the armchair edges, we find that it would be extremely hard to desorb the H from their adsorption sites at the armchair edges. Furthermore, we also found that, consistent with our earlier conclusions [cf., J. Phys. Soc. Jpn. 72 (2003) 1867], it is unlikely that we would find a whole H_2 in between plain graphite sheets.Comment: 4 pages, 5 figures, preprin

Magnetic-adsorbate-induced spin polarization in carbon materials - Two Fe atoms on planar C10 and C10H8

Here we consider a nanoscale material consisting of two Fe atoms sitting on a planar C10 cluster. On the basis of the density functional theory (DFT), we demonstrate how it is feasible to induce spin polarization on an initially nonmagnetic carbon material by introducing magnetic adsorbates, and how the presence of hydrogen reduces the induced polarization. © 2003 The Physical Society of Japan

PPS-metal adhesion: a density functional theory-based study

We investigate the adhesion of poly (phenylene sulfide) (PPS) on aluminum, copper, silver and gold through simulations involving PPS monomers and single metal atoms. Density functional theory based-total energy calculation results show that PPS binds best to aluminum through the sulfur end of the monomer. Although adhesion to copper is strongest in the other two schemes examined, the energy curves suggest that these may not proceed directly. The models involving silver in general showed the least affinity for PPS adhesion. © 2004 Elsevier Ltd. All rights reserved