Quantitative Measurement of the Surface Self-Diffusion on Au Nanoparticles by Aberration-Corrected Transmission Electron Microscopy

• Published in: Nano letters Vol. 12; no. 12; pp. 6071 - 6077
• Main Authors: Surrey, A, Pohl, D, Schultz, L, Rellinghaus, B
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 12.12.2012
• Subjects: Aberration; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Diffusion coefficient; Diffusion in nanoscale solids; Diffusion in solids; Electron microscopy; Exact sciences and technology; Gold; Imaging; Instability; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Nanocrystalline materials; Nanoparticles; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Physics; Reconstruction; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Transport properties of condensed matter (nonelectronic); gold; surface reconstruction; nanoparticles; Surface diffusion; aberration-corrected HRTEM; diffusion coefficient; Gold; Fluctuations; Nanostructures; Nanoparticles; Surface reconstruction; Electron beams; Transmission electron microscopy; Aberrations; Imaging; Instability; Diffusion coefficient; Nanostructured materials; Self-diffusion
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl302280x

We present a method that allows for a quantitative measurement of the surface self-diffusion on nanostructures, such as nanoparticles, at the atomic scale using aberration-corrected high-resolution transmission electron microscopy (HRTEM). The diffusion coefficient can be estimated by measuring the fluctuation of the atom column occupation at the surface of Au nanoparticles, which is directly observable in temporal sequences of HRTEM images. Both a Au icosahedron and a truncated Au octahedron are investigated, and their diffusion coefficients are found to be in the same order of magnitude, D = 10–17 to 10–16 cm2/s. It is to be assumed that the measured surface diffusion is affected by the imaging electron beam. This assumption is supported by the observed instability of a (5 × 1) surface reconstruction on a {100} Au facet.