Single-shot 3D coherent diffractive imaging of core-shell nanoparticles with elemental specificity

Area of Science:

• Materials Science
• Nanotechnology
• X-ray Physics

Background:

• Characterizing nanoparticle structure and elemental composition at the nanoscale is crucial for advanced materials development.
• Traditional imaging techniques often lack the resolution or elemental specificity required for complex nanostructures.

Purpose of the Study:

• To develop and demonstrate a 3D coherent diffractive imaging (CDI) method for high-resolution, elemental-specific imaging of Au/Pd core-shell nanoparticles.
• To achieve nanoscale structural and compositional analysis beyond conventional imaging limits.

Main Methods:

• Utilized intense X-ray Free Electron Laser (XFEL) pulses to measure single-shot diffraction patterns.
• Reconstructed 3D electron density using CDI, exploiting Ewald sphere curvature and nanoparticle symmetry.
• Implemented a super-resolution technique combined with high-resolution model fitting for quantitative analysis.

Main Results:

• Achieved 6.1 nm spatial resolution in 3D imaging of Au/Pd core-shell nanoparticles.
• Accurately determined gold core size (65.0 ± 1.0 nm) and palladium shell thickness (4.0 ± 0.5 nm).
• Identified 3D elemental distribution with 3% accuracy, validated through simulations.

Conclusions:

• The developed super-resolution CDI method enables quantitative 3D imaging of nanostructures with elemental specificity.
• This technique offers a powerful tool for analyzing complex nanomaterials, paving the way for new material design.
• The method is anticipated for general application to symmetrical nanostructures.