Low-Energy Electron Diffraction Study of Graphite

Abstract

A low‐energy electron diffraction study of surface properties of single‐crystal graphite revealed that unlike silicon, germanium, or diamond, the basal plane at the surface was not reconstructed nor did it chemisorb H₂O, O₂, CO, Br₂, or I₂ in monolayer quantities at low pressures and moderate or high temperatures. Elastic and inelastic electron scattering factors for graphite and their contributions to diffraction effects have also been evaluated. The layered structure serves to simplify certain analytical problems and, in particular, results in an energy region from about 10 to 70 V where one‐dimensional analysis provides first‐order estimates of these scattering factors. But it is also seen that from the point of view of complete and precise quantitative analysis, the elastic and inelastic scattering amplitudes, phase effects, three‐dimensional effects, and dynamic factors are almost inextricably entangled in the energy region below about 70 V. Above this region the diffraction effects are largely kinematic and analysis is much simpler.