Auger decay mechanism in photon-stimulated desorption of ions from surfaces [electronic resource]
Saved in:
| Online Access: |
Online Access |
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| Corporate Authors: | , |
| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Berkeley, Calif. : Oak Ridge, Tenn. :
Lawrence Berkeley National Laboratory ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy,
1983.
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| Abstract: | Photon-stimulated desorption (PSD) of positive ions was studied with synchrotron radiation using an angle-integrating time-of-flight mass spectrometer. Ion yields as functions of photon energy near core levels were measured from condensed gases, alkali fluorides, and other alkali and alkaline earth halides. These results are compared to bulk photoabsorption measurements with emphasis on understanding fundamental desorption mechanisms. The applicability of the Auger decay mechanism, in which ion desorption is strictly proportional to surface absorption, is discussed in detail. The Auger decay model is developed in detail to describe Na⁺ and F⁺ desorption from NaF following Na(1s) excitation. The major decay pathways of the Na(1s) hole leading to desorption are described and equations for the energetics of ion desorption are developed. Ion desorption spectra of H⁺, Li⁺, and F⁺ are compared to bulk photoabsorption near the F(2s) and Li(1s) edges of LiF. A strong photon beam exposure dependence of ion yields from alkali fluorides is revealed, which may indicate the predominance of metal ion desorption from defect sites. The large role of indirect mechanisms in ion desorption condensed N₂-O₂ multilayers is demonstrated and discussed. Ion desorption spectra from several alkali halides and alkaline earth halides are compared to bulk photoabsorption spectra. Relative ion yields from BaF₂ and a series of alkali halides are discussed in terms of desorption mechanisms. |
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| Item Description: | Published through the Information Bridge: DOE Scientific and Technical Information. 11/01/1983. "lbl-16892" "DE84004351" Parks, C.C. |
| Physical Description: | Pages: 156 : digital, PDF file. |