Structure retrieval at atomic resolution in the presence of multiple scattering of the electron probe

TL;DR

This paper presents a method to reconstruct atomic-resolution electrostatic potentials in thick crystals from STEM data, overcoming previous limitations related to multiple scattering and sample thickness.

Contribution

It introduces a practical inversion technique for multiple scattering equations, enabling atomic-resolution imaging in thicker samples than previously possible.

Findings

Successful reconstruction of electrostatic potential at atomic resolution in thick crystals

Overcomes limitations of ultrathin sample restriction in electron microscopy

Potential for improved imaging with existing and upcoming electron microscopes

Abstract

The projected electrostatic potential of a thick crystal is reconstructed at atomic-resolution from experimental scanning transmission electron microscopy data recorded using a new generation fast- readout electron camera. This practical and deterministic inversion of the equations encapsulating multiple scattering that were written down by Bethe in 1928 removes the restriction of established methods to ultrathin ($\lesssim 50$ {\AA}) samples. Instruments already coming on-line can overcome the remaining resolution-limiting effects in this method due to finite probe-forming aperture size, spatial incoherence and residual lens aberrations.