Direct imaging of core-shell structure in silver-gold bimetallic nanoparticles

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Authors

Colleges, School and Institutes

Abstract

High-angle annular dark field imaging in the electron microscope has been exploited to reveal the internal structure of monodispersed, bimetallic gold (Au) - silver (Ag) nanoparticles of similar to 4 nm diameter, prepared using a seed-growth wet chemical method and passivated with an organic layer. Starting with a 3 nm Ag seed particle, deposition of Au atoms to a final overall atomic ratio of Ag:Au=1:2 leads to nanoparticles with an Ag-rich core and an Au-rich shell, as expected. If the overall atomic ratio is 2:1, the core/shell structure is not observed. The physical significance of these observations is discussed in terms of the stability of particles of nanoscale dimensions. (c) 2005 American Institute of Physics.

Details

Original languageEnglish
Pages (from-to)243103
Number of pages1
JournalApplied Physics Letters
Volume87
Publication statusPublished - 1 Jan 2005