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Title: Structural investigation of self-irradiation damaged AmO{sub 2}

Studying self-irradiated materials is an ideal means to investigate the effect of the damage on material structure and to better understand the behavior of irradiated nuclear fuels. In this context, X-ray diffraction, X-ray absorption spectroscopy and transmission electron microscopy have been used to investigate self-irradiation damaged AmO{sub 2}. Combining these techniques allows studying the microstructure and the variation of the fluorite structure at both short-range and long-range order. Thus, the increase of both interatomic distances and lattice parameter was shown, as well as the presence of nanometer sized He bubbles and dislocation loops. As confirmed by the observed high-level of crystallinity, the fluorite structure exhibits a high radiation tolerance, which is confirmed by the low increase of the lattice parameter. This could be explained by a self-annealing mechanism of the created defects at room temperature. - Graphical abstract: The structure of damaged AmO2 (36 dpa) has been studied by XRD, XAS and TEM. Thus, the effects of the self-irradiation on the oxidation state, the lattice distances, the structural disorder, the radiation stability and the microstructure have been discussed. - Highlights: • The structure of highly self-irradiated AmO{sub 2} (36 dpa) was studied by XAS and TEM. • XRD, EXAFS andmore » TEM confirm the high stability of the fluorite structure. • XRD and EXAFS show an increase of 0.3% of the structural distances. • XANES shows that Am is tetravalent as well as the Np recoil nucleus. • The presence of He bubbles was evidenced by TEM.« less
Authors:
 [1] ; ; ;  [1] ;  [2] ; ;  [1]
  1. European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany)
  2. Institut für Nukleare Entsorgung, Hermann-von-Helmholtz-Platz, 76344 Eggenstein-Leopoldshafen (Germany)
Publication Date:
OSTI Identifier:
22334157
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 212; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION SPECTROSCOPY; AMERICIUM OXIDES; ATOMIC DISPLACEMENTS; FLUORITE; INTERATOMIC DISTANCES; LATTICE PARAMETERS; MICROSTRUCTURE; SELF-IRRADIATION; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY