Quantitative structure determination from experimental four-dimensional scanning transmission electron microscopy via the scattering matrix

TL;DR

This paper advances a scattering matrix method for reconstructing the electrostatic potential of thick samples in four-dimensional scanning transmission electron microscopy, effectively handling partial coherence, defocus, and dark field data to improve accuracy.

Contribution

It extends the scattering matrix approach to better accommodate experimental complexities like partial coherence and defocus, enhancing quantitative structure determination.

Findings

Successful reconstruction of SrTiO₃ crystal potential with good quantitative agreement.

Demonstrated robustness of the method against partial coherence and defocus effects.

Enhanced algorithm for structure determination from complex 4D-STEM data.

Abstract

Considerable inroads have recently been made on algorithms to determine the sample potential from four-dimensional scanning transmission electron microscopy data from thick samples where multiple scattering cannot be neglected. This paper further develops the scattering matrix approach to such structure determination. Through simulation, we demonstrate how this approach can be modified to better handle partial spatial coherence, unknown probe defocus, and information from the dark field region. By combining these developments we reconstruct the electrostatic potential of a monolithic SrTiO$_3$ crystal showing good quantitative agreement with the expected structure.