Acoustic Vibrations in Bimetallic Au@Pd Core-Shell Nanorods.
The acoustic vibrations of gold nanorods coated with palladium were investigated as a function of Pd amount using ultrafast pump-probe spectroscopy. Both the extensional and breathing vibrational modes of the nanorods were coherently excited and detected. This permits precise determination of their periods, which were found to decrease and increase with Pd deposition, for the extensional and vibrational modes, respectively. These opposite behaviors reflect changes of the nanoparticle size and mechanical properties, in agreement with numerical simulations. Comparison of experimental and computed periods yields information on the amount of deposited Pd, providing a novel tool to characterize bicomponent nano-objects for small fractions of one of the components (Pd/Au atomic fraction down to 5%).
†Departamento de Quimica Fisica, Universidade de Vigo, 36310 Vigo, Spain.|‡International Iberian Nanotechnology Laboratory, Braga, 4710229, Portugal.
M Fernanda
MF
Cardinal
§FemtoNanoOptics Group, Université Lyon 1, CNRS, LASIM, 43 Bd du 11 Novembre, 69622 Villeurbanne, France.
Denis
D
Mongin
§FemtoNanoOptics Group, Université Lyon 1, CNRS, LASIM, 43 Bd du 11 Novembre, 69622 Villeurbanne, France.
Aurélien
A
Crut
§FemtoNanoOptics Group, Université Lyon 1, CNRS, LASIM, 43 Bd du 11 Novembre, 69622 Villeurbanne, France.
Paolo
P
Maioli
†Departamento de Quimica Fisica, Universidade de Vigo, 36310 Vigo, Spain.
Benito
B
Rodríguez-González
†Departamento de Quimica Fisica, Universidade de Vigo, 36310 Vigo, Spain.
Jorge
J
Pérez-Juste
†Departamento de Quimica Fisica, Universidade de Vigo, 36310 Vigo, Spain.
Luis M
LM
Liz-Marzán
§FemtoNanoOptics Group, Université Lyon 1, CNRS, LASIM, 43 Bd du 11 Novembre, 69622 Villeurbanne, France.
Natalia
N
Del Fatti
§FemtoNanoOptics Group, Université Lyon 1, CNRS, LASIM, 43 Bd du 11 Novembre, 69622 Villeurbanne, France.
Fabrice
F
Vallée
acoustic vibrations of nanoparticles; core−shell nanoparticles; finite element modeling; gold nanorods; nanosensors; time-resolved spectroscopy