AVS 46th International Symposium
    Applied Surface Science Division Wednesday Sessions
       Session AS-WeA

Paper AS-WeA9
XPS and UPS Characterization of Single Crystal NaNO@sub 3@ and NaNO@sub 2@: Influence of Laser Irradiation at 248 nm

Wednesday, October 27, 1999, 4:40 pm, Room 6A

Session: Oxides and Insulators
Presenter: C. Bandis, Washington State University
Authors: C. Bandis, Washington State University
S.C. Langford, Washington State University
J.T. Dickinson, Washington State University
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Inorganic nitrates are susceptible to radiation damage, including laser and x-ray irradiation. The critical role of radiation induced chemistry is studied utilizing monochromatised X-ray photoelectron spectroscopy (XPS) and He II (40.8 eV) ultraviolet photoemission spectroscopy (UPS). Photoelectron emission from single crystal NaNO@sub 3@ and NaNO@sub 2@ cleaved and laser or x-ray irradiated surfaces shows that the observed changes in the spectra due to laser irradiation are similar with those observed due to X-ray exposure. Our observations suggest that in both cases (laser and X-ray irradiation) the NaNO@sub 3@ decomposition is initiated by the pi-pi* transition in the NO@sub 3@@super -@ anion. Direct comparison of our experimental UPS and XPS valence band electron energy distributions with recent calculations of the total density of states shows good agreement between theory and experiment for both NaNO@sub 3@ and NaNO@sub 2@. We also report on the influence of such surface modification on the laser desorption of ions and neutrals from cleaved NaNO@sub 3@ single crystal surfaces. This work was supported by the Department of Energy (DE-FG03-98ER14864) and the National Science Foundation (DMR-9503304).