Radiation-Enhanced Aqueous Dissolution of Minerals
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Radiation-Enhanced Aqueous Dissolution of Minerals Catherine A. Dukes1 and Raúl A. Baragiola1 1
Laboratory for Atomic and Surface Physics, University of Virginia, Materials Science and Engineering, 395 McCormick Road, Charlottesville, VA 22904 ABSTRACT
Mineral samples of varying petrology, exposed to ion irradiation and subsequently immersed in water or exposed to a humid environment, show up to 60% depletion of specific surface atoms (Mg, Ca, K, and Na) — a depletion that is enhanced 26,000x compared to unirradiated surfaces. Surface depletions of irradiated minerals exposed to water were measured using X-ray photoelectron spectroscopy. Irradiations were performed with 4 keV Ar+ ions at fluences from 1014 – 1019 ion cm-2; samples were subsequently exposed to liquid water or humid air (35º C and 70% RH). Analyses were done before irradiation, after irradiation, and after exposure to water, allowing identification of changes in composition due solely to ion irradiation or combined with water exposure. Before water exposure, we observe no significant change in stoichiometry of the minerals for ion fluences
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