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

A. Surrey †‡, D. Pohl †‡, L. Schultz †‡, and B. Rellinghaus *†

^† IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden, Germany

^‡ TU Dresden, Institut für Festkörperphysik, D-01062 Dresden, Germany

Nano Lett., Article ASAP

DOI: 10.1021/nl302280x

Publication Date (Web): November 8, 2012

Copyright © 2012 American Chemical Society

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^–16cm²/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.