21 July 1994 Dynamics of photodesorption of small particles bound to cluster surfaces
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Proceedings Volume 2125, Laser Techniques for Surface Science; (1994) https://doi.org/10.1117/12.180848
Event: OE/LASE '94, 1994, Los Angeles, CA, United States
Abstract
The photodesorption of Na atoms from Na clusters deposited on dielectric surfaces is investigated via pulsed laser excitation and cw two-photon laser-induced fluorescence detection. The combination of pulsed excitation and cw detection within the focii of two counterpropagating lasers provides high spatial resolution (allowing one to obtain accurate angular and kinetic energy distributions) while at the same time preserving the high temporal resolution given by the pulsed laser. Moreover, spatial overlap of desorption and detection lasers on the surface facilitates to follow directly the conversion of initial surface plasmon excitation into bond-breaking in the clusters or phonon excitation in the substrate. It is found that the final step of photodesorption of Na from large Na clusters bound to mica surfaces can be described via multiphonon scattering of the desorbing particles from the surface of the clusters (with nearly zero initial kinetic energy). By use of lithium fluoride as the supporting substrate it is observed that the activation energy for photodesorption from the clusters depends on the Debye temperature of the supporting substrate. This emphasizes the need to include coupling between clusters and substrate in order to understand the overall desorption process.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Frank Balzer, M. Renger, Horst-Guenter Rubahn, "Dynamics of photodesorption of small particles bound to cluster surfaces", Proc. SPIE 2125, Laser Techniques for Surface Science, (21 July 1994); doi: 10.1117/12.180848; https://doi.org/10.1117/12.180848
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