Correcting for probe wandering by precession path segmentation

TL;DR

This paper introduces a novel precession path segmentation method that leverages fast pixelated detectors to correct probe wandering in precession electron diffraction, enhancing image resolution and reducing alignment issues.

Contribution

A new post-processing technique using detector data to correct probe wandering, improving resolution and easing instrument alignment in precession electron diffraction.

Findings

Increased resolution of reconstructed images.

Reduced probe wandering due to misalignment.

Potentially simplified alignment procedures.

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.