Structural investigations of (La, Pu)PO4 monazite solid solutions: XRD and XAFS study

JOURNAL OF NUCLEAR MATERIALS

卷:493

Article

Arinicheva, Yulia¹  Popa, Karin²  Scheinost, Andreas C.³  Rossberg, Andre³  Dieste-Blanco, Oliver²  Raison, Philippe²  Cambriani, Andrea²  Somers, Joseph²  Bosbach, Dirk¹  Neumeier, Stefan¹ 

[1] Forschungszentrum Julich, Inst Energy & Climate Res Nucl Waste Management &, D-52425 Julich, Germany

[2] European Commiss, Joint Res Ctr, D-76125 Karlsruhe, Germany

[3] Helmholtz Zentrum Dresden Rossendorf, Inst Resource Ecol, D-01314 Dresden, Germany

关键词: Plutonium;    Monazite;    Waste form;    Solid state synthesis;    Solid solutions;    XRD;    EXAFS;   

DOI  :  10.1016/j.jnucmat.2017.06.034

来源: Elsevier

【 摘 要 】

A solid state method was used to synthesize La1-xPuxPO4 (x = 0.01, 0.05, 0.10, 0.15, (0.5)) solid solutions with monazite structure. XRD measurements of the compounds with x = 0.50 revealed the formation of two phases: (La, Pu) PO4-monazite and a cubic phase (PuO2). Pure-phase La1-xPuxPO4-monazite solid solutions were obtained for materials with x = 0.00-0.15 and confirmed by a linear dependence of the lattice parameters on composition according to Vegard's law. X-ray absorption spectroscopy (XAS) analysis at the Pu-L-III and La-L-III edges confirmed the +III valence state of plutonium in the monazite solid solutions. The local environment of Pu is PuPO4-like along the solid solution series, except for the longest fitted cation-cation distance, which may be an indication of cluster formation consisting of a few Pu-atoms in the La-Pu-monazite lattice. (C) 2017 The Authors. Published by Elsevier B.V.

【 授权许可】

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