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FP7

EXAFS study of the structural phase transition in the americium zirconate pyrochlore

Funded under: FP7-EURATOM

Abstract

The {241}Am(2)Zr(2)O(7) phase undergoes a structural transition from pyrochlore to defect fluorite driven by alpha self-irradiation. In an effort to better understand the underlying phenomena of this order-disorder transition, powder X-ray diffraction (PXRD) and X-ray absorption fine-structure (XAFS) spectroscopy experiments were conducted on two samples aged for 40 days (0.02 dpa) and 370 days (0.21 dpa), respectively. While the XAFS data support the phase transition observed by XRD, they reveal different local coordinations of americium and zirconium. The transition occurs through oxygen Frenkel and cation antisite formation. The XAFS, clearly showed that the ZrO polyhedron is stable against irradiation, probably a main factor explaining the excellent resistance to amorphization observed for americium zirconia defect fluorite structures.

Additional information

Authors: MARTIN PM, Département de Recherches sur la Fusion Contrôlée, Association Euratom-CEA sur la Fusion, CEA Cadarache, Saint-Paul-lez-Durance (FR);BELIN RC, Département de Recherches sur la Fusion Contrôlée, Association Euratom-CEA sur la Fusion, CEA Cadarache, Saint-Paul-lez-Durance (FR);VALENZA PJ, Département de Recherches sur la Fusion Contrôlée, Association Euratom-CEA sur la Fusion, CEA Cadarache, Saint-Paul-lez-Durance (FR);SCHEINOST AC, Forschungszentrum Dresden-Rossendorf (FZD), Institute of Radiochemistry, Dresden (DE)
Bibliographic Reference: An article published in: Journal of Nuclear Materials (2008), Article in Press, Corrected Proof
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://dx.doi.org/10.1016/j.jnucmat.2008.10.028
Record Number: 200910142 / Last updated on: 2009-01-23
Category: PUBLICATION
Original language: en
Available languages: en
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