Quantitative Analysis of Polycrystalline Electron Diffraction Patterns

Image processing and computer-assisted analysis are very important in electron microscopy/crystallography, e.g., computer programs have been well developed for image processing and simulation for high-resolution electron microscopy images, and are widely used in research. Unfortunately, few computer programs have been developed for analysis and processing electron diffraction ring patterns. Facing this situation, Labar [1] developed ProcessDiffraction, a computer program to process electron diffraction patterns from polycrystalline and amorphous samples, with an aim to provides good angular resolution, quantified intensities, and reproducible identification of discontinuous and/or faint rings. For phase identification, it is to compare the generated diffractogram to the X-ray diffraction data bases. Li [2] developed JECP/PCED, a computer program for simulation of polycrystalline electron diffraction pattern and phase identification, which uses the raw or processed diffraction pattern as the input file and directly match to the simulated ring pattern. Both of the programs have proved to be fast yet accurate for phase identification.