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arXiv · 2209.06787

Measurement of atomic modulation direction using the azimuthal variation of first order Laue zone electron diffraction

Aurys Silinga·Christopher S. Allen·Juri Barthel·Colin Ophus·Ian MacLaren
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Abstract

We show that diffraction intensity into the First Order Laue Zone (FOLZ) of a crystal can have a strong azimuthal dependence, where this FOLZ ring appears solely because of unidirectional atom position modulation. Such a modulation was already known to cause the appearance of elliptical columns in atom resolution images, but we show that measurement of the angle via 4-dimensional Scanning Transmission Electron Microscopy (4DSTEM) is far more reliable and allows the measurement of the modulation direction with a precision of about 1{\deg} and an accuracy of about 3{\deg}. This method could be very powerful in characterising atomic structures in 3 dimensions by 4DSTEM, especially in cases where the structure deviates from that found in bulk crystals.

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Aurys Silinga, Christopher S. Allen, Juri Barthel, Colin Ophus, Ian MacLaren. 2022-09-14. Measurement of atomic modulation direction using the azimuthal variation of first order Laue zone electron diffraction. https://doi.org/10.1093/micmic%2Fozad089

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