RAPID : an ImageJ macro for indexing electron diffraction zone axis spot patterns of cubic materials

Journal of Applied Crystallography, vol. 57, pp. 2017–2029

Abstract

As an extension to previous work, the ImageJ macro script RAPID (ratio-method pattern indexing) has been developed to allow instant indexing of calibrated and uncalibrated zone axis aligned electron diffraction patterns of cubic lattices using the R n ratio principle. The program can be used to index zone axis aligned selected-area electron diffraction patterns, nanobeam electron diffraction patterns, transmission electron microscopy (TEM) Kikuchi patterns and even fast Fourier transforms of high-resolution (scanning) TEM images. The program allows the user to quickly assess whether the material under investigation belongs to the cubic crystal system, is pseudo-cubic or is not cubic at all by adjusting the boundary parameters and allowed errors for lattice indexing. The software also allows one to distinguish between the P , I and F Bravais lattices for certain zone axis directions. For calibrated diffraction patterns, the lattice parameters can be obtained, allowing verification of the material under investigation or phase identification in connection with a structural database. In addition, the program can be employed for determination or verification of the used instrument's camera constant when reference materials are used. Therefore, it is a convenient tool for on-site crystallographic analysis in TEM laboratories.

Authors 1

1. Thomas E. Weirich corresponding Aachen Gemeinschaftslabor für Elektronenmikroskopie (GFE)

   RWTH Aachen University

   Affiliation as printed

   Gemeinschaftslabor für Elektronenmikroskopie (GFE) RWTH Aachen University Ahornstrasse 55 52074Aachen Germany

   Gemeinschaftslabor für Elektronenmikroskopie (GFE), RWTH Aachen University, Ahornstrasse 55, 52074 Aachen, Germany