title: Surface and Epitaxial Stresses on Supported Metal Clusters.
abstract: Surface stress and energy are basic quantities in the Gibbsian formulation of the thermodynamic description of surfaces which is central in the formation and long-term behavior of materials at the nanoscale. However, their size dependence is a puzzling issue. It is even unclear whether they decrease or increase with decreasing particle size. In addition, for a given metal, estimates often span over an order of magnitude, far apart from bulk data, which, in the absence of any explicit size-dependence rule, escapes understanding. Here, we combine X-ray absorption and nanoplasmonics data with atomistic simulation to describe α-Al2O3(0001)-supported silver particles. By comparison to MgO(001)-supported and embedded silver, we distinguish epitaxial and surface stress. The latter is shown to dominate above 3 nm in size. Since the observation mostly relies on surface/bulk ratio, a metal-independent picture emerges that is expected to have far-reaching consequences for the understanding of the energetics of nanoparticles.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7588 , Institut des NanoSciences de Paris, F-75005 Paris, France.
authors.forename: Rémi
authors.initials: R
authors.lastname: Lazzari
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7588 , Institut des NanoSciences de Paris, F-75005 Paris, France.
authors.forename: Jacek
authors.initials: J
authors.lastname: Goniakowski
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7588 , Institut des NanoSciences de Paris, F-75005 Paris, France.
authors.forename: Gregory
authors.initials: G
authors.lastname: Cabailh
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7588 , Institut des NanoSciences de Paris, F-75005 Paris, France.
authors.forename: Rémi
authors.initials: R
authors.lastname: Cavallotti
authors.affiliation: Synchrotron SOLEIL, L'Orme des Merisiers, St-Aubin, BP48, F-91192 Gif sur Yvette, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Trcera
authors.affiliation: Synchrotron SOLEIL, L'Orme des Merisiers, St-Aubin, BP48, F-91192 Gif sur Yvette, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Lagarde
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7588 , Institut des NanoSciences de Paris, F-75005 Paris, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Jupille
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D008277:Magnesium Oxide / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D008277:Magnesium Oxide; D012834:Silver; D000537:Aluminum Oxide
keywords: Stress; X-ray absorption; atomistic simulations; epitaxy; plasmonics; silver nanoparticle