The structure of samples of amorphous hydrogenated carbon, prepared from acetylene and propane precursors, containing 35 and 32 at. % hydrogen, respectively, was investigated by time-of-flight neutron diffraction in the range 0.2--50 A^-1 using the ISIS spallation source. The large dynamic range of the data ensures a real-space resolution sufficient to reveal directly the proportions of sp² and sp³ hybridized carbon. The results show that, in these hard carbon materials, the carbon-atom sites are predominantly sp² bonded, and the carbon-carbon single bond:carbon-carbon double bond ratio is about 2.5:1. The detailed information on atomic correlations thus provided is used to discuss current structural models, and in particular the data are used to show that these models require significant modification.
No takes yet. Share an insight, caveat, or question.
Walters et al. (1994) studied this question.