On the structure of {100} platelet defects in type la diamond

The elucidation of defect structure using two-dimensional lattice images is a difficult and time-consuming procedure owing to the number of variable experimental parameters in a high resolution experiment. In this paper the most important experimental parameters are determined prior to the attempt at structure determination, using a number of different techniques including image matching of perfect diamond images and matching the width and appearance of the central Fresnel fringe at the platelet. Having determined the experimental parameters, the image matching was then carried out using five different models for the platelet. It is found that the high resolution two-dimensional lattice images are sensitive to platelet structure and are consistent with a previously unknown platelet model, the double nitrogen layer zigzag model.