Phase imaging in scanning transmission electron microscopy using bright-field balanced divergency method

TL;DR

This paper presents a novel phase imaging method for scanning transmission electron microscopy that enhances resolution, robustness, and efficiency, enabling detailed atomic and nanoscale magnetic phase imaging.

Contribution

The paper introduces a new phase imaging technique exploiting intensity changes at different scattering angles, improving resolution and robustness over conventional methods.

Findings

Detects both light and heavy atomic columns at atomic resolution

Demonstrates imaging of nanoscale magnetic phases in FeGe

Offers higher spatial resolution and noise robustness

Abstract

We introduce a phase imaging mechanism for scanning transmission electron microscopy that exploits the complementary intensity changes of transmitted disks at different scattering angles. For scanning transmission electron microscopy, this method provides a straightforward, dose-efficient, and noise-robust phase imaging, from atomic resolution to intermediate length scales, as a function of scattering angles and probe defocus. At atomic resolution, we demonstrate that the phase imaging using the method can detect both light and heavy atomic columns. Furthermore, we experimentally apply the method to the imaging of nanoscale magnetic phases in FeGe samples. Compared with conventional methods, phase retrieval using the new method has higher effective spatial resolution and robustness to non-phase background contrast. Our method complements traditional phase imaging modalities in electron microscopy and has the potential to be extended to other scanning transmission techniques and to characterize many emerging material systems.