Probing confined acoustic phonons in free standing small gold nanoparticles

Polarized and depolarized spectra from gold (Au) nanoparticles of different sizes are investigated in the small size range, between 3 and 7 nm, using low frequency Raman spectroscopy. Acoustic vibrations of the free-standing Au nanoparticles are demonstrated with frequencies ranging from 5 to 35 cm−...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied physics 2013-02, Vol.113 (7)
Main Authors: Mankad, Venu, Jha, Prafulla K., Ravindran, T. R.
Format: Article
Language:English
Subjects:
Acoustics
Blue shift
CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
Depolarization
GOLD
Low frequencies
Nanoparticles
NANOSCIENCE AND NANOTECHNOLOGY
NANOSTRUCTURES
PHONONS
RAMAN EFFECT
RAMAN SPECTRA
RAMAN SPECTROSCOPY
RESONATORS
SPECTRAL SHIFT
TRANSMISSION ELECTRON MICROSCOPY
Vibration
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Polarized and depolarized spectra from gold (Au) nanoparticles of different sizes are investigated in the small size range, between 3 and 7 nm, using low frequency Raman spectroscopy. Acoustic vibrations of the free-standing Au nanoparticles are demonstrated with frequencies ranging from 5 to 35 cm−1, opening the way to the development of the acoustic resonators. A blue shift in the phonon peaks along with the broadening is observed with a decrease in particle size. Comparison of the measured frequencies with vibrational dynamics calculation and an examination as from the transmission electron microscopy results ascertain that the low frequency phonon modes are due to acoustic phonon quantization. Our results show that the observed low frequency Raman scattering originates from the spherical (l = 0) and quadrupolar (l = 2) vibrations of the spheroidal mode due to plasmon mediated acoustic vibrations in Au nanoparticles.
ISSN:0021-8979
1089-7550
DOI:10.1063/1.4792654