Accelerate TEM Data Analysis with
Electron Crystallography Tools
RAPID (RAtio method Pattern InDexing) is an ImageJ macro script developed for the quick determination of sample orientation and indexing of calibrated and uncalibrated zone axis aligned electron diffraction patterns from materials with a cubic crystal structure. In addition to conventional SAED patterns, the program is also capable of handling zone axis TEM Kikuchi patterns and FFTs derived from HR(S)TEM images. The software enables users to rapidly determine whether materials are cubic, pseudo-cubic, or non-cubic, and to distinguish between P, I, F and diamond lattices. It can also provide lattice parameters for material verification and aid in determining the camera constant of the instrument, thus making the program a convenient tool for on-site crystallographic analysis in the TEM laboratory.
FINDS is an ImageJ macro script that assists in the evaluation of selected area electron diffraction (SAED) patterns that contain numerous diffraction spots arranged on concentric but incomplete rings. The program allows the user to mark diffraction spots of known phases by overlaying rings on the pattern, making it easy to identify and address additional (unidentified) reflections between them. In addition to the full functionality for calculating and plotting the diffraction ring patterns of known phases in different styles and colours, FINDS also provides tools for locating spot positions and determining the corresponding d-values of the reflections of interest.
RIPAS (RIng PAttern Simulation) is a user-friendly native cross-platform desktop application designed for simulating electron powder diffractograms of both amorphous and crystalline materials. For the calculation of the diffraction patterns, the program only requires the interplanar spacings (d values) of the material and, if available, the corresponding reflection intensities. The patterns generated by the program can be superimposed on experimental diffraction patterns for ease of analysis and documentation.
CELLFINDER is an ImageJ script that determines the 2D unit cell from the peaks in HAADF STEM images by using angle-resolved lattice population density (ALPD) plots. As the maxima in ALPD plots represent the lines with the highest atom peak density, the cell angle of the primitive 2D unit cell can be readily identified, and a 2D unit cell can be constructed. Furthermore, the introduction of angle constraints for the selection of ALPD maxima allows the identification of 2D unit cell sizes that comply with crystallographic standards.
UNITCELL SAED has been developed for the ImageJ/Fiji platform to obtain precise 2D unit cell parameters from selected area electron diffraction (SAED) patterns aligned along a zone axis. In addition to error analysis based on comparison of observed and calculated d-spacings, the program allows the verification of different 2D symmetries and supports the re-indexing of 2D HK indices to 3D hkl indices for subsequent use with other crystallographic software.