Correcting for probe wandering by precession path segmentation

Gregory Nordahl; Lewys Jones; Emil Frang Christiansen; Kasper Aas Hunnestad; Magnus Nord

doi:10.1016/j.ultramic.2023.113715

Correcting for probe wandering by precession path segmentation

Ultramicroscopy. 2023 Jun:248:113715. doi: 10.1016/j.ultramic.2023.113715. Epub 2023 Mar 8.

Authors

Gregory Nordahl¹, Lewys Jones², Emil Frang Christiansen³, Kasper Aas Hunnestad⁴, Magnus Nord³

Affiliations

¹ Department of Physics, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway. Electronic address: gregory.nordahl@ntnu.no.
² School of Physics, Trinity College Dublin, Dublin 2, Ireland; Advanced Microscopy Laboratory, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Dublin 2, Ireland.
³ Department of Physics, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.
⁴ Department of Materials Science and Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.

PMID: 36924599
DOI: 10.1016/j.ultramic.2023.113715

Abstract

Precession electron diffraction has in the past few decades become a powerful technique for structure solving, strain analysis, and orientation mapping, to name a few. One of the benefits of precessing the electron beam, is increased reciprocal space resolution, albeit at a loss of spatial resolution due to an effect referred to as 'probe wandering'. Here, a new methodology of precession path segmentation is presented to counteract this effect and increase the resolution in reconstructed virtual images from scanning precession electron diffraction data. By utilizing fast pixelated electron detector technology, multiple frames are recorded for each azimuthal rotation of the beam, allowing for the probe wandering to be corrected in post-acquisition processing. Not only is there an apparent increase in the resolution of the reconstructed images, but probe wandering due to instrument misalignment is reduced, potentially easing an already difficult alignment procedure.

Keywords: Aberrations; Alignment; Electron diffraction; Precession.