Three-dimensional atomic imaging of crystalline nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Electron Microscopy

Background:

• Accurate 3D atomic arrangement determination in crystalline nanoparticles is crucial for nanometre-scale device engineering, optoelectronics, and catalysis.
• Nanoparticle properties are dictated by their 3D morphology, structure, and composition.
• Conventional electron tomography has not achieved atomic resolution in three dimensions, despite decades of atomic-resolution electron microscopy in 2D.

Purpose of the Study:

• To report the first 3D reconstruction of a complex crystalline nanoparticle at atomic resolution.
• To overcome the limitations of existing experimental techniques for 3D atomic-scale imaging.

Main Methods:

• Combined aberration-corrected scanning transmission electron microscopy (STEM) with statistical parameter estimation theory and discrete tomography.
• Utilized only two projection images of a silver nanoparticle embedded in an aluminium matrix, leveraging prior crystallographic knowledge.
• Confirmed reconstruction reliability with additional projections.

Main Results:

• Successfully achieved atomic resolution in the three-dimensional reconstruction of a crystalline nanoparticle.
• Demonstrated that a minimal number of projections (two) are sufficient for high-resolution 3D reconstruction when combined with crystallographic information.
• Bridged the resolution gap between 2D electron microscopy and existing 3D techniques.

Conclusions:

• The developed method provides unprecedented 3D atomic-scale insight into nanoparticle structure.
• This technique significantly advances the capability to characterize and engineer nanomaterials.
• Opens new avenues for understanding structure-property relationships in nanomaterials for advanced applications.