CIOP   05384
CENTRO DE INVESTIGACIONES OPTICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Optical spectroscopy extinction method for sizing noble metal nanoparticles generated by femtosecond laser ablation of solid in liquids
Autor/es:
D. C. SCHINCA, ; L. B. SCAFFARDI, ; G. A. TORCHIA, ; F. A. VIDELA, ; J. M. J. SANTILLÁN, ; P. MORENO ; L. ROSO
Lugar:
Palacio de Congresos Salamanca, España
Reunión:
Conferencia; 10th European Conference on Atoms, Molecules and Photons, 4 9 july 2010, Palacio de Congresos Salamanca, España; 2010
Institución organizadora:
10th European Conference on Atoms, Molecules and Photons
Resumen:
In the last
years, there has been an increasing interest in the generation of nanostructures
using different methods. Concurrently, there is a constant need for sizing
techniques at the nanoscale. Most frequently, the standard method is based on
transmission electron microscopy (TEM). Although resolution can be good enough,
sample preparation is cumbersome and statistics may be poor.
Optical
methods arise as an alternative to TEM with competitive resolution and easiness of
sample handling. These methods rely basically on absorption or transmission
measurements [1,2]. In this work we present results of sizing small silver
and gold colloidal nanoparticles generated by fs laser ablation in water and ethanol
by fitting their optical extinction spectra. This fitting is based on the electrostatic
approximation of Mie theory for particles much smaller than the incident wavelength.
We show that, for the case of silver nanoparticles, the presence of a silver oxide
shell around the silver bare core affects certain characteristics of the
extinction spectrum, such as resonance wavelength, FWHM and
contrast, which can be used for sizing purposes. Optical extinction spectra of nanoparticles
generated with different fluences are used as fitting examples which show good agreement
with TEM distribution measurements.
These
relations may also be the base for the development of a parametric method that
can be readily applied to single particle spectroscopy sizing.
[1] G. A.
Torchia, L. B. Scaffardi, Cruz Méndez, Pablo Moreno, J. O. Tocho and Luis Roso,
Applied Physics A: Material Science & Processing, 93, pp. 967-9, 2008
[2] D. C. Schinca,
L. B. Scaffardi, F. A. Videla, G. A. Torchia, P. Moreno and L. Roso, J. Phys. D: Appl. Phys.
42, pp 215102-11,2009