New approaches to nanoparticle sample fabrication for atom probe tomography.

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Nano-sized materials like nanoparticles and nanowires exhibit unique properties, driving significant research interest.
• A critical knowledge gap exists regarding the atomic-scale, three-dimensional (3D) chemical composition of these nanomaterials.
• Atom probe tomography (APT) offers high-resolution chemical analysis but requires specialized sample preparation for nanomaterials.

Purpose of the Study:

• To detail various techniques for positioning nanoparticles on substrates for atom probe tomography analysis.
• To enable high-resolution 3D chemical mapping of nano-sized materials.

Main Methods:

• Development and description of techniques for precise nanoparticle positioning on substrate tips.
• Integration of deposition techniques to embed nanoparticles within a solid matrix.
• Utilizing focused ion beam (FIB) processing to fabricate APT-suitable samples from composite materials.

Main Results:

• Successful positioning and analysis of 10-20 nm core-shell nanoparticles.
• Achieved atomic-scale chemical mapping with a resolution better than ± 1 nm.
• Demonstrated analysis of nanoparticles directly from suspension without chemical modification.

Conclusions:

• The described methods overcome sample preparation challenges for APT analysis of nanoparticles.
• This advancement allows for unprecedented 3D chemical characterization of nanomaterials at the atomic scale.
• The techniques are applicable to various nano-sized materials, facilitating deeper understanding of their properties.