High resolution powder electron diffraction in scanning electron microscopy

0549414 - ÚMCH 2022 RIV CH eng J - Článek v odborném periodiku
Šlouf, Miroslav - Skoupý, Radim - Pavlova, Ewa - Krzyžánek, Vladislav
High resolution powder electron diffraction in scanning electron microscopy.
Materials. Roč. 14, č. 24 (2021), č. článku 7550. E-ISSN 1996-1944
Grant CEP: GA TA ČR(CZ) TN01000008; GA ČR(CZ) GA21-13541S
Institucionální podpora: RVO:61389013 ; RVO:68081731
Klíčová slova: nanoparticle analysis * powder nanobeam electron diffraction * 4D-STEM
Obor OECD: Polymer science; Electrical and electronic engineering (UPT-D)
Impakt faktor: 3.748, rok: 2021
Způsob publikování: Open access
https://www.mdpi.com/1996-1944/14/24/7550

A modern scanning electron microscope equipped with a pixelated detector of transmitted electrons can record a four-dimensional (4D) dataset containing a two-dimensional (2D) array of 2D nanobeam electron diffraction patterns, this is known as a four-dimensional scanning transmission electron microscopy (4D-STEM). In this work, we introduce a new version of our method called 4D-STEM/PNBD (powder nanobeam diffraction), which yields high-resolution powder diffractograms, whose quality is fully comparable to standard TEM/SAED (selected-area electron diffraction) patterns. Our method converts a complex 4D-STEM dataset measured on a nanocrystalline material to a single 2D powder electron diffractogram, which is easy to process with standard software. The original version of 4D-STEM/PNBD method, which suffered from low resolution, was improved in three important areas: (i) an optimized data collection protocol enables the experimental determination of the point spread function (PSF) of the primary electron beam, (ii) an improved data processing combines an entropy-based filtering of the whole dataset with a PSF-deconvolution of the individual 2D diffractograms and (iii) completely re-written software automates all calculations and requires just a minimal user input. The new method was applied to Au, TbF3 and TiO2 nanocrystals and the resolution of the 4D-STEM/PNBD diffractograms was even slightly better than that of TEM/SAED.
Trvalý link: http://hdl.handle.net/11104/0325682