||I U P A C
Organizations & People
Pure Appl. Chem. Vol.
72, Nos. 1-2, pp. 189-197, 2000
Special Topic Issue on the Theme of
Photophysics and spectroscopy of metal particles
Josł H. Hodak*, Arnim Henglein, and Gregory V. Hartland
* Department of Chemistry and Biochemistry, University
of Notre Dame, Notre Dame, Indiana 46556-5670, USA
Abstract: This paper describes our recent work using ultrafast
laser spectroscopy to examine the fundamental properties of metal particles.
Two studies are presented. First, the characteristic time scale for
electron-phonon coupling in Au particles with sizes between 2 and 120
nm has been examined by bleach recovery measurements. These experiments
show that the coupling between the electrons and phonons is independent
of particle size, to within the signal-to-noise of our experiments.
We have also used transient absorption spectroscopy to examine the low-frequency
"breathing" modes of the Au particles. These modes are impulsively
excited by the rapid lattice heating that accompanies electron-phonon
coupling. The breathing motion contributes to the transient absorption
signal because the position of the plasmon band depends on the free
electron density and, thus, the particle volume. The measured frequencies
are inversely proportional to the radius, and almost exactly match the
predictions of classical mechanics calculations for Au.
Back to Contents for access to full
Page last modified 5 May 2000.
Copyright ©2000 International Union of Pure and Applied Chemistry.
Questions or comments about IUPAC, please contact, the Secretariat.
Questions regarding the website, please contact web