Strain and Crystallographic Identification of the Helically Concaved Surfaces of Nanoparticles

TL;DR

This paper presents a novel X-ray imaging method to visualize 3D crystal structures and strain distributions in chiral gold nanoparticles, aiding in understanding their optical and catalytic properties.

Contribution

Developed a Bragg coherent X-ray diffraction imaging technique to precisely map 3D crystallography and strain in complex chiral nanoparticles, linking structure to plasmonic behavior.

Findings

Resolved high-Miller-index planes in concave chiral gaps

Mapped highly strained regions adjacent to chiral gaps

Predicted plasmonic properties from atomic structures

Abstract

Identifying the three-dimensional (3D) crystal-plane and strain-field distributions of nanocrystals is essential for optical, catalytic, and electronic applications. Here, we developed a methodology for visualizing the 3D information of chiral gold nanoparticles with concave gap structures by Bragg coherent X-ray diffraction imaging. The distribution of the high-Miller-index planes constituting the concave chiral gap was precisely determined. The highly strained region adjacent to the chiral gaps was resolved, which was correlated to the 432-symmetric morphology of the nanoparticles and its corresponding plasmonic properties were numerically predicted from the atomically defined structures. This approach can serve as a general characterization platform for visualizing the 3D crystallographic and strain distributions of nanoparticles, especially for applications where structural complexity and local heterogeneity are major determinants, as exemplified in plasmonics.