Local and Electronic Structure of Americium-Bearing PuO2

X-ray Diffraction and X-ray Absorption Spectroscopy have shown that a material composed of two (Pu,Am)O2-x substoichiometric fluorite-type structures is obtained by sintering in moisturized Ar-H2. The Pu oxidation state is, surprisingly, strictly (+IV) while Am exhibits a (+III/+IV) mixed valence. Thus, the Am-O system and particularly the Am oxidation state play a major role in the sintering behavior of the Pu-Am-O system. The heating of this compound in air leads to the formation of a fluorite Pu0.80Am0.20O1.98 solid solution. The transition from one phase to two phase structure takes place in a temperature inferior to 800°C. The results were compared with previous studies on Am bearing UO2 and ThO2 which have evidenced different behaviors.

PRIEUR Damien;  CARVAJAL NUNEZ Ursula;  VITOVA T.;  SOMERS Joseph; 

2013-04-17

WILEY-BLACKWELL

JRC75776

1434-1948,   

http://onlinelibrary.wiley.com/doi/10.1002/ejic.201201294/full,    https://publications.jrc.ec.europa.eu/repository/handle/JRC75776,   

10.1002/ejic.201201294,