Size and surface structure of diamond nano-crystals

High-resolution transmission electron microscopy and electron nano-diffraction patterns provide useful information concerning the size distribution and surface condition of nano-crystalline diamond powder produced by shock detonation. Analysis of X-ray powder diffractometer data, using the Debye equation to predict the powder profile, starting with a set of spherical diamond ball models, allows the mean size to be obtained for bulk quantities of the same powders. The electron powder diffraction patterns for some diamond spheres, and also spherical shell, models of the surface structures were calculated using the Debye equation, and compared with experiment. It is suggested that the surface structure may become accessible to diffraction methods, if a single nano-crystal is irradiated and both the single crystal pattern plus the diffuse scattering are recorded, as a function of the orientation of that single crystal.