Mössbauer spectroscopy of europium-containing glasses: Optical activator study for x-ray image plates.
A fluorozirconate glass (ZBLAN) containing BaCl2nanocrystals doped with divalent Eu is a promising material for x-ray image plates for medical diagnosis. Since it is known that Eu2+readily oxidizes to Eu3+, which reduces fluorescence efficiency of the image plates,151Eu Mössbauer spectroscopy was used in this work to monitor the Eu oxidation state of the samples during degradation over time in the presence of ambient humidity. In addition, Mössbauer spectroscopic experiments show that the oxidation state has already changed during the glass melt: The sample made from 5 mol% EuCl2contained 78% EuCl2+ 22% EuCl3deduced from the relative areas of the absorption lines. The sample made from 2.5 mol% EuCl2+ 2.5 mol% EuCl2contained 37% EuCl2+ 63% EuCl3, i.e. 26% of the original EuCl2was oxidized to EuCl3.
University of Tennessee Space Institute, Tullahoma, TN 37388, USA.
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Johnson
University of Tennessee Space Institute, Tullahoma, TN 37388, USA.
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Vu
University of Tennessee Space Institute, Tullahoma, TN 37388, USA.
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Johnson
Northern Illinois University, DeKalb, IL 60115, USA.
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Brown
Materials Development Inc., Arlington Heights, IL 60004, USA.
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Weber
Centre for Innovation Competence SiLi-nano, Martin Luther University of Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3, 06120 Halle (Saale), Germany.
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Paßlick
Centre for Innovation Competence SiLi-nano, Martin Luther University of Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3, 06120 Halle (Saale), Germany, and Fraunhofer Center for Silicon Photovoltaics, Walter-Hülse-Str. 1, 06120 Halle (Saale), Germany.
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Schweizer