Atomic Structure and 3D Shape of a Multibranched Plasmonic Nanostar from a Single Spatially Resolved Electron Diffraction Map

Author(s)

Correa, Leonardo M. ; Fairclough, Simon M. ; Scher, Kaleigh M. R. ; Atta, Supriya ; dos Santos, Diego Pereira ; Ducati, Caterina ; Fabris, Laura ; Ugarte, Daniel

• Document type: Journal article
• Source: ACS NANO; v. 18, n. 39, p. 11-pg., 2024-09-21.

Abstract

Despite the interest in improving the sensitivity of optical sensors using plasmonic nanoparticles (NPs) (rods, wires, and stars), the full structural characterization of complex shape nanostructures is challenging. Here, we derive from a single scanning transmission electron microscope diffraction map (4D-STEM) a detailed determination of both the 3D shape and atomic arrangement of an individual 6-branched AuAg nanostar (NS) with high-aspect-ratio legs. The NS core displays an icosahedral structure, and legs are decahedral rods attached along the 5-fold axes at the core apexes. The NS legs show an anomalous anisotropic spatial distribution (all close to a plane) due to an interplay between the icosahedral symmetry and the unzipping of the surfactant layer on the core. The results significantly improve our understanding of the star growth mechanism. This low dose diffraction mapping is promising for the atomic structure study of individual multidomain, multibranched, or multiphase NPs, even when constituted of beam-sensitive materials. (AU)

• FAPESP's process: 14/01045-0 - Advanced electron microscopy studies of metallic clusters and nanocomposites materials for photovoltaic applications
• Grantee: Daniel Mario Ugarte
• Support Opportunities: Scholarships abroad - Research
• FAPESP's process: 22/11983-4 - Spectroscopy signal enhancement: nanomaterials, theory, and computer simulation
• Grantee: Mauro Carlos Costa Ribeiro
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/21070-5 - Vibrational spectroscopy with spatial resolution
• Grantee: Mauro Carlos Costa Ribeiro
• Support Opportunities: Research Projects - Thematic Grants