Probing elasticity at the nanoscale: Terahertz acoustic vibration of small metal nanoparticles.
The acoustic response of surface-controlled metal (Pt) nanoparticles is investigated in the small size range, between 1.3 and 3 nm (i.e., 75-950 atoms), using time-resolved spectroscopy. Acoustic vibration of the nanoparticles is demonstrated, with frequencies ranging from 1.1 to 2.6 THz, opening the way to the development of THz acoustic resonators. The frequencies, measured with a noncontact optical method, are in excellent agreement with the prediction of a macroscopic approach based on the continuous elastic model, together with the bulk material elastic constants. This demonstrates the validity of this model at the nanoscale and the weak impact of size reduction on the elastic properties of a material, even for nanoparticles formed by less than 100 atoms.
Juvé
Vincent
V
Université Lyon 1, CNRS, LASIM, 43 bd du 11 Novembre 1918, Villeurbanne cedex, France.
Crut
Aurélien
A
Maioli
Paolo
P
Pellarin
Michel
M
Broyer
Michel
M
Del Fatti
Natalia
N
Vallée
Fabrice
F
D000162:Acoustics; D055119:Elastic Modulus; D008422:Materials Testing / Q000379:methods; D015336:Molecular Probe Techniques; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010984:Platinum / Q000737:chemistry*; D055068:Terahertz Spectroscopy / Q000379:methods*; D014732:Vibration
D010984:Platinum