title: Metastability of the atomic structures of size-selected gold nanoparticles.
abstract: All nanostructures are metastable--but some are more metastable than others. Here we employ aberration-corrected electron microscopy and atomistic computer simulations to demonstrate the hierarchy of metastability in deposited, size-selected gold nanoparticles (clusters), an archetypal class of nanomaterials well known for the catalytic activity which only appears on the nanometer-scale. We show that the atomic structures presented by "magic number" Au561, Au742 and Au923 clusters are "locked". They are in fact determined by the solidification which occurs from the liquid state early in their growth (by assembly from atoms in the gas phase) followed by template growth. It is quite likely that transitions from a locked, metastable configuration to a more stable (but still metastable) structure, as observed here under the electron beam, will occur during catalytic reactions, for example.
authors: Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK. R.E.Palmer@bham.ac.uk.
authors: Dawn M
authors: DM
authors: Wells
authors: Giulia
authors: G
authors: Rossi
authors: Riccardo
authors: R
authors: Ferrando
authors: Richard E
authors: RE
authors: Palmer