Physics – Condensed Matter – Soft Condensed Matter
Scientific paper
2003-05-11
Physics
Condensed Matter
Soft Condensed Matter
Scientific paper
10.1103/PhysRevE.67.062402
We propose an explanation for the recently measured slow fluctuations and ``blinking'' in the surface enhanced Raman scattering (SERS) spectrum of single molecules adsorbed on a silver colloidal particle. We suggest that these fluctuations may be related to the dynamic relaxation of the surface roughness on the nanometer scale and show that there are two classes of roughness with qualitatively different dynamics. The predictions agree with measurements of surface roughness relaxation. Using a theoretical model for the kinetics of surface roughness relaxation in the presence of charges and optical electrical fields, we predict that the high-frequency electromagnetic field increases both the effective surface tension and the surface diffusion constant and thus accelerates the surface smoothing kinetics and time scale of the Raman fluctuations in manner that is linear with the laser power intensity, while the addition of salt retards the surface relaxation kinetics and increases the time scale of the fluctuations. These predictions are in qualitative agreement with the Raman experiments.
Haran Gilad
Lukatsky David B.
Safran Samuel A.
No associations
LandOfFree
Slow fluctuations in enhanced Raman scattering and surface roughness relaxation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Slow fluctuations in enhanced Raman scattering and surface roughness relaxation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Slow fluctuations in enhanced Raman scattering and surface roughness relaxation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-90177