| Numéro |
J. Phys. IV France
Volume 129, October 2005
|
|
|---|---|---|
| Page(s) | 51 - 54 | |
| DOI | https://doi.org/10.1051/jp4:2005129011 | |
J. Phys. IV France 129 (2005) 51-54
DOI: 10.1051/jp4:2005129011
Confined acoustic modes in nanoparticles
Y. Li, H.S. Lim, Z.K. Wang, S.C. Ng and M.H. KuokDepartment of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542
Abstract
Brillouin scattering from aggregates of monodisperse
polystyrene spheres has been measured as a function of their diameters (20 - 990 nm). In this range of sphere sizes studied, confined acoustic modes and
two types of bulk longitudinal acoustic modes are observed. One type exists
within larger spheres (diameter > 700 nm), while the other propagates in
aggregates of smaller spheres (diameter 
80 nm) which are considered
as polystyrene-air composites. The frequencies of the confined acoustic
modes are found to be proportional to inverse sphere diameter, in accordance
with Lamb's theory.
© EDP Sciences 2005