Structural properties of amorphous hydrogenated carbon. II. An inelastic neutron-scattering study

Inelastic-neutron-scattering experiments have been performed on samples of amorphous hydrogenated carbon, prepared from acetylene and propane, containing about 35 and 32 at. % hydrogen, respectively. In these hard carbons, the hydrogen is predominantly bonded to ${\mathit{sp}}^3$ carbon, with approximately equal concentrations of CH and ${\mathrm{CH}}_2$ groups. There is little hydrogen in other bonding environments, and a small amount of ${\mathrm{H}}_2$ is trapped in cages in the material.