Table of Contents
Laser Chemistry
Volume 20, Issue 1, Pages 23-32
http://dx.doi.org/10.1080/02786270212132

Laser Ablation Studies of Deposited Silver Colloids Active in SERS

1Instituto de Química Física “Rocasolano”, C.S.I.C., Serrano 119, Madrid 28006, Spain
2Instituto de Estructura de la Materia, C.S.I.C., Serrano 121, Madrid 28006, Spain
3Institute for Electronic Structure and Laser, FORTH, P.O, Box 1527, Heraklio 711 10, Greece

Received 21 May 2001

Copyright © 2002 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Laser ablation of deposited silver colloids, active in SERS, is carried out at three different laser wavelengths (KrF, XeCl and Nd:YAG at λ = 248, 308 and 532 nm respectively). Emission form excited neutral Ag and Na atoms, present in the ablation plume, is detected with spectral and temporal resolution. The expansion velocity of Ag in the plume is estimated in ~1×104ms1. Low-fluence laser ablation of the colloids yields ionized species that are analyzed by time-of-flight mass spectroscopy. Na+ and Agn+(n3) are observed. Composition of the mass spectra and widths of the mass peaks are found to be dependent on laser wavelength, suggesting that the dominant ablation mechanisms are different at the different wavelenghts.