Atomic-resolution imaging of surface and core melting in individual size-selected Au nanoclusters on carbon

Research output: Contribution to journalArticle

Authors

  • Dawn Foster
  • Th Pavloudis
  • J. Kioseoglou
  • R. E. Palmer

Colleges, School and Institutes

External organisations

  • Nanoscale Physics Research Laboratory
  • Swansea University
  • Aristotle University of Thessaloniki

Abstract

Although the changes in melting behaviour on the nanoscale have long attracted the interest of researchers, the mechanism by which nanoparticles melt remains an open problem. We report the direct observation, at atomic resolution, of surface melting in individual size-selected Au clusters (2–5 nm diameter) supported on carbon films, using an in situ heating stage in the aberration corrected scanning transmission electron microscope. At elevated temperatures the Au nanoparticles are found to form a solid core-liquid shell structure. The cluster surface melting temperatures, show evidence of size-dependent melting point suppression. The cluster core melting temperatures are significantly greater than predicted by existing models of free clusters. To explore the effect of the interaction between the clusters and the carbon substrate, we employ a very large-scale ab initio simulation approach to investigate the influence of the support. Theoretical results for surface and core melting points are in good agreement with experiment.

Details

Original languageEnglish
Article number2583
Number of pages8
JournalNature Communications
Volume10
Issue number1
Early online date13 Jun 2019
Publication statusE-pub ahead of print - 13 Jun 2019