title: Acoustic vibrations of metal-dielectric core-shell nanoparticles.
abstract: The acoustic vibrations of metal nanoparticles encapsulated in a dielectric shell (Ag@SiO(2)) were investigated using a time-resolved femtosecond technique. The measured vibration periods significantly differ from those predicted for the bare metal cores and, depending on the relative core and shell sizes, were found to be either larger or smaller than them. These results show that the vibration of the whole core-shell particle is excited and detected. Moreover, vibrational periods are in excellent agreement with the predictions of a model based on continuum thermoelasticity. However, such agreement is obtained only if a good mechanical contact of the metal and dielectric parts of the core-shell particle is assumed, providing a unique way to probe this contact in multimaterial or hybrid nano-objects.
authors.affiliation: FemtoNanoOptics group, LASIM, Université Lyon 1-CNRS, 43 Bd du 11 Novembre, 69622 Villeurbanne, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Mongin
authors.forename: Vincent
authors.initials: V
authors.lastname: Juvé
authors.forename: Paolo
authors.initials: P
authors.lastname: Maioli
authors.forename: Aurélien
authors.initials: A
authors.lastname: Crut
authors.forename: Natalia
authors.initials: N
authors.lastname: Del Fatti
authors.forename: Fabrice
authors.initials: F
authors.lastname: Vallée
authors.forename: Ana
authors.initials: A
authors.lastname: Sánchez-Iglesias
authors.forename: Isabel
authors.initials: I
authors.lastname: Pastoriza-Santos
authors.forename: Luis M
authors.initials: LM
authors.lastname: Liz-Marzán
mesh_terms: D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors; D014732:Vibration
chemical_list: D012834:Silver; D012822:Silicon Dioxide