COLL 133 |
| Small metal particles are of interest in a variety of applications, from molecular sensing to catalysis. Research in my group is concerned with using time-resolved optical spectroscopy to study the properties of the particles. The traces obtained in these experiments are rich in information. The initial and overall decays yield the timescales for electron-phonon coupling and interface conductance. Modulations due to vibrational modes that are coherently excited by laser induced heating are also observed. Comparison of the measured periods to the continuum mechanics results yields information about the elastic constants of the particles. For symmetric shapes, such as spheres or cubes, the breathing modes are predominantly excited. For more complicated geometries – such as rods – different modes are observed. In most cases the measured elastic constants are the same as the bulk metal, with the exception of the extensional mode of gold nanorods, where a significant softening is observed. |
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Electrochemistry-Enabled Nano S&T
2:00 PM-5:00 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 227, Oral
Division of Colloid & Surface Chemistry |