Two-color laser desorption of nanostructured MgO thin films |
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Authors: | Kenneth M. Beck |
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Affiliation: | Environmental Molecular Sciences Laboratory, Chemical and Materials Science Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352, USA |
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Abstract: | Neutral magnesium atom emission from nanostructured MgO thin films is induced using two-color nanosecond laser excitation. We find that combined vis/UV excitation, for single-color pulse energies below the desorption threshold, induces neutral Mg-atom emission with hyperthermal kinetic energies in the range of 0.1-0.2 eV. The observed metal atom emission is consistent with a mechanism involving rapid electron transfer to three-coordinated Mg surface sites. The two-color Mg-atom signal is significant only for parallel laser polarizations and temporally overlapped laser pulses indicating that intermediate excited states are short-lived compared to the 5 ns laser pulse duration. |
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Keywords: | 61.82.Rx 79.20.La 71.35.&minus y 77.55.+f 77.84.Bw |
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