5/19/2023 0 Comments Tem diffraction pattern analysis![]() Part I presents the principles, while future publication of Parts II and III will elaborate on current implementation and will demonstrate its usage by examples, respectively. Parameters of the peak shapes and the other experimental parameters are refined by exploring the parameter space with the help of the Downhill-SIMPLEX. The Blackman correction is applied to the set of kinematic diffraction lines to take into account dynamic effects for medium grain size. The textured fraction is determined as a separate component by fitting the spectral components, calculated for the previously identified phases with a priori known structures, to the measured distribution. Both randomly oriented nanopowders and textured nanopowders, observed from the direction of the texture axis produce such SAED patterns. Fractions of the different nanocrystalline components are determined from rotationally symmetric ring patters. This article describes a method that performs (semi)quantitative phase analysis for nanocrystalline samples from selected area electron diffraction (SAED) patterns. Application of electron diffraction (DF imaging, dislocation contrast, phase identification etc. polycrystalline diffraction, selected area diffraction etc.), Indexing of diffraction pattern (camera constant, structure. Nowadays, TEM laboratories encounter many thin samples with grain size in the 1–30 nm range, not too far from the kinematic ED conditions. Concept of reciprocal lattice, Ewald sphere, diffraction from finite crystal. A method for phase analysis, similar to the Rietveld method in X-ray diffraction, was not developed for electron diffraction (ED) in the transmission electron microscope (TEM), mainly due to the dynamic nature of ED.
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