Neutron-scattering studies of the structure of highly tetrahedral amorphous diamondlike carbon

Abstract

The structure of a-C prepared by plasma-arc deposition has been determined by neutron scattering and analyzed to estimate the fraction of tetrahedrally and trigonally bonded carbons. The structure factor and reduced radial distribution functions are similar to those for a-Si and a-Ge, indicating a high proportion of tetrahedral bonding. Also, the mean value of the nearest-neighbor C-C distance is close to that of crystalline diamond and a fit to the data gives about 86% tetrahedral bonding. This form of diamondlike carbon therefore appears to be the structural equivalent of a-Si and a-Ge.