Exploring the atomic structure of 1.8 nm monolayer-protected gold clusters with aberration-corrected STEM

Jian Liu, Isabel Mecking Ornelas, Alexander Pattison, Tanja Lahtinen, Kirsi Salorinne, Hannu Häkkinen, Richard Palmer

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)
140 Downloads (Pure)

Abstract

Monolayer-protected (MP) Au clusters present attractive quantum systems with a range of potential applications e.g. in catalysis. Knowledge of the atomic structure is needed to obtain a full understanding of their intriguing physical and chemical properties. Here we employed aberration-corrected scanning transmission electron microscopy (ac-STEM), combined with multislice simulations, to make a round-robin investigation of the atomic structure of chemically synthesized clusters with nominal composition Au144(SCH2CH2Ph)60 provided by two different research groups. The MP Au clusters were “weighed” by the atom counting method, based on their integrated intensities in the high angle annular dark field (HAADF) regime and calibrated exponent of the Z dependence. For atomic structure analysis, we compared experimental images of hundreds of clusters, with atomic resolution, against a variety of structural models. Across the size range 123 to 151 atoms, only 3 percent of clusters matched the theoretically predicted Au144(SR)60 structure, while a large proportion of the clusters were amorphous (i.e. did not match any model structure). However, a distinct ring-dot feature, characteristic of local icosahedral symmetry, was observed in about 20% of the clusters.
Original languageEnglish
JournalUltramicroscopy
Early online date22 Nov 2016
DOIs
Publication statusE-pub ahead of print - 22 Nov 2016

Keywords

  • Monolayer-Protected Gold Clusters
  • Aberration-Corrected STEM
  • Au144(SR)60
  • Atom counting method
  • Atomic structure

Fingerprint

Dive into the research topics of 'Exploring the atomic structure of 1.8 nm monolayer-protected gold clusters with aberration-corrected STEM'. Together they form a unique fingerprint.

Cite this