Mechanism of hollow nanoparticle formation due to shape fluctuations

Shape fluctuations in nanoparticles strongly influence their stability. Here, we introduce a quantitative model of such shape fluctuations and apply this model to the important case of Pt-shell/transition metal-core nanoparticles. By using a Gibbs distribution for the initial shapes, we find that th...

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Bibliographic Details
Published inPhysical review letters Vol. 112; no. 15; p. 155505
Main Authors Erlebacher, J, Margetis, D
Format Journal Article
LanguageEnglish
Published United States 18.04.2014
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Summary:Shape fluctuations in nanoparticles strongly influence their stability. Here, we introduce a quantitative model of such shape fluctuations and apply this model to the important case of Pt-shell/transition metal-core nanoparticles. By using a Gibbs distribution for the initial shapes, we find that there is typically enough thermal energy at room temperature to excite random shape fluctuations in core-shell nanoparticles, whose amplitudes are sufficiently high that the cores of such particles are transiently exposed to the surrounding environment. If this environment is acidic and dissolves away the core, then a hollow shell containing a pinhole is formed; however, this pinhole quickly closes, leaving a hollow nanoparticle. These results favorably compare to experiment, much more so than competing models based on the room-temperature Kirkendall effect.
ISSN:1079-7114
DOI:10.1103/physrevlett.112.155505