Materials Structure, Properties and Dynamics through Scanning Transmission Electron Microscopy

TL;DR

Recent advances in scanning transmission electron microscopy (STEM) enable atomic-scale imaging and analysis with minimal damage, revealing detailed material structures, compositions, and dynamics at unprecedented precision.

Contribution

This paper reviews the recent technological developments in STEM that allow for atomic-resolution imaging, analysis, and dynamic studies of materials.

Findings

Atomic-sized beams enable high-resolution imaging at low voltages.

Aberration correction improves image quality and analysis capabilities.

STEM allows real-time observation of defect dynamics and charge transfer.

Abstract

Scanning transmission electron microscopy (STEM) has advanced rapidly in the last decade thanks to the ability to correct the major aberrations of the probe forming lens. Now atomic-sized beams are routine, even at accelerating voltages as low as 40 kV, allowing knock-on damage to be minimized in beam sensitive materials. The aberration-corrected probes can contain sufficient current for high quality, simultaneous, imaging and analysis in multiple modes. Atomic positions can be mapped with picometer precision, revealing ferroelectric domain structures, composition can be mapped by energy dispersive X-ray spectroscopy (EDX) and electron energy loss spectroscopy (EELS) and charge transfer can be tracked unit cell by unit cell using the EELS fine structure. Furthermore, dynamics of point defects can be investigated through rapid acquisition of multiple image scans. Today STEM has become an indispensable tool for analytical science at the atomic level, providing a whole new level of insights into the complex interplays that control materials properties.