On the Use of Precession Electron Diffraction for Minerals Characterization: From Twinning Identification to Structure Refinement

The precession electron diffraction (PED) technique [1] has been originally developed for structure determination at a submicrometer scale in a transmission electron microscope (TEM). Since, many structures have been solved using PED, recently combined with the tomographic acquisition of 3D electron diffraction data [2]. Using PED, integrated intensities of the diffracted beams as a function of the rocking beam orientation are collected. The resulting intensities keep dynamical in nature, due to residual multiple scattering, but are more closely related to the strength of the scattering events and ranking of reflections as a function of their intensities is generally correlated to the structure factor values, which is crucial for structure solution and refinement [3].