The simplest case includes calculating the characteristic distances in different crystallographicĭirections using Bragg’s equation, and comparing the obtained values The interpretation of diffraction patterns obtained from two-dimensional and quasi-3D systems can be very time-consuming work at different investigation levels. Indexing of crystal structures can be done by analyzing diffraction patterns. Standard indexed electron diffraction patterns However, they still need to manually index new patterns or to identify unfamiliar ones.įigure 4825 shows an example of indexing a cubic crystal plane.
Therefore, they can recognize a zone axis from the symmetry of the pattern and thus easily identify many patterns just by looking at them. Experienced microscopists can take shortcuts because they remember some obvious symmetries, such as a square or hexagonal array of spots for a cubic crystal. We can perform indexing electron diffraction patterns in various ways, depending on how much information we already know about the specimen. In general, indexing electron diffraction patterns is an empirical work with theoretical understandings. Simply speaking, the process of indexing electron diffraction patterns of a single crystal is to label the individual diffraction spots with their proper values and sign (+ or -) of h, k, and l. This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.
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