Degree Type

Dissertation

Date of Award

1989

Degree Name

Doctor of Philosophy

Department

Physics and Astronomy

First Advisor

D. W. Lynch

Abstract

Electron beam induced decompositions of alkali halides were studied. Compositional and topological changes induced by low-energy electron irradiation have been observed on thin films and single crystals of alkali-halides using scanning electron microscopy (SEM) and Auger electron microscopy (SAM). Alkali-metal rich structures with diameters of up to several microns were found on the sample surfaces;The temperature dependence of desorption yields were measured using a mass-spectrometer. We observed two temperature regions, each features a different activation Oil, Gas, and Energy;Temperature dependence of electron induced decomposition of CaF2 was studied using Auger spectroscopy and Energy dispersive x-ray (EDX) analysis. We observed that the decrease of surface concentration of F due to desorption does not depend on temperature while the decrease of bulk concentration does, and the activation energy of this process was measured.

DOI

https://doi.org/10.31274/rtd-180813-9007

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Qun Dou

Language

en

Proquest ID

AAI9014893

File Format

application/pdf

File Size

98 pages

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