New insights on the thermal decomposition of lanthanideIII and actinideIII oxalates: from neodymium and cerium to plutoniumReport as inadecuate




New insights on the thermal decomposition of lanthanideIII and actinideIII oxalates: from neodymium and cerium to plutonium - Download this document for free, or read online. Document in PDF available to download.

* Corresponding author 1 CEA-DEN - CEA-Direction de l-Energie Nucléaire 2 AREVA 3 IJL - Institut Jean Lamour 4 Labex DAMAS

Abstract : Lanthanides are often used as surrogates to study the properties of actinide compounds. Their behaviour is considered to be quite similar as they both possess f valence electrons and are close in size and chemical properties. This study examines the potential of using two lanthanides neodymium and cerium as surrogates for plutonium during the thermal decomposition of isomorphic oxalate compounds, in the trivalent oxidation state, into oxides. Thus, the thermal decomposition of neodymium, cerium and plutonium III oxalates are investigated by several coupled thermal analyses TG-DTA-DSC-MS-FT-IR and complementary characterisation techniques XRD, UV-vis, FT-IR, SEM, carbon analyser under both oxidizing and inert atmosphere. The thermal decomposition mechanisms determined in this study confirmed some previous results reported in the literature, among diverging propositions, while also elucidating some original mechanisms not previously considered. Calculated thermodynamic and kinetic parameters for the studied systems under both atmospheres are reported and compared with available literature data. Similarities and differences between the thermal behaviour of plutoniumIII and lanthanideIII oxalates are outlined.

Keywords : Neodymium Cerium Plutonium Oxalate Redox Thermal decomposition Mechanisms Thermodynamics Kinetics Carbon Boudouard





Author: Lucie De Almeida - Stéphane Grandjean - Nicolas Vigier - Fabrice Patisson -

Source: https://hal.archives-ouvertes.fr/



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