Charge distribution and local structure of americium bearing thorium oxide solid solutions

The electronical and structural properties of Th0.80Am0.20O2-x materials have been studied by the coupling X-Ray Diffraction (XRD) and X-ray Absorption Spectroscopy (XAS) techniques. A substoichiometric fluorite Th(+IV)0.80Am(+III)0.20O1.90 solid solution is found following sintering in moisturised Ar-H2. In contrast, heating of this sample in air leads to a non-defective fluorite Th(+IV)0.80Am(+IV)0.20O2.00 solid solution. The structure of these solid solutions compounds were fully characterised by assessing the interatomic distances, the coordination numbers and the structural disorder. The effect of sintering atmosphere on these crystallographical parameters and on the cation valences has been determined and the capability of ThO2 to accommodate tri- and quatravalent actinides in the fluorite structure assessed.

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

2012-12-14

AMER CHEMICAL SOC

JRC73273

0020-1669,   

http://pubs.acs.org/doi/full/10.1021/ic301709d,    https://publications.jrc.ec.europa.eu/repository/handle/JRC73273,   

10.1021/ic301709d,