Reduction of Eu{sup 3+} to Eu{sup 2+} in aluminoborosilicate glasses under ionizing radiation
- Laboratoire des Solides Irradies, UMR 7642 CEA-CNRS-Ecole Polytechnique, 91128 Palaiseau Cedex (France)
Eu{sub 2}O{sub 3}-doped aluminoborosilicate glasses were prepared by melting in air at high temperature ({approx}1500 {sup o}C). It was shown by luminescence and Electron Paramagnetic Resonance (EPR) measurements that both Eu{sup 3+} and Eu{sup 2+} ions can exist simultaneously in the glass matrix studied after glass synthesis as well as after exposure to ionizing radiation. Increase of total Eu{sub 2}O{sub 3} concentration leads to the increase of Eu{sup 3+} luminescence intensity while the luminescence intensity of Eu{sup 2+} ions tends to decrease. In contrast the EPR indicates that the amount of Eu{sup 2+} ions in the glass increases with total Eu{sub 2}O{sub 3} concentration. The difference in the results of the two spectroscopies is explained in terms of energy transfer from Eu{sup 2+} to Eu{sup 3+} leading to an Eu{sup 2+} luminescence quenching. Irradiation results in the increase of reduced Eu{sup 2+} quantity detected by EPR measurements. It was shown that Eu{sup 2+} ions are located in both high (g {approx} 4.6) and low symmetry ('U' spectrum) sites in the structure of aluminoborosilicate glasses. The increase of Eu{sup 2+} content by the increase of the irradiation dose manifests the strong reduction process Eu{sup 3+} {yields} Eu{sup 2+}.
- OSTI ID:
- 22207390
- Journal Information:
- Materials Research Bulletin, Vol. 45, Issue 9; Other Information: Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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