Lattice contraction and lattice deformation of UO2 and ThO2 doped with Gd2O3

Angela Baena, Thomas Cardinaels, Kevin Govers, Janne Pakarinen, Marc Verwerft, Koen Binnemans

    Research outputpeer-review

    Abstract

    "The lattice deformations in two doped fluorite systems, (U1-xGdx)O2.00 and (Th1‑xGdx)O2-x/2, have been reassessed by precise X-ray and electron diffraction investigations and the results were interpreted using the Bond Valence Sum (BVS) approach. For the (U1-xGdx)O2.00 system, the experimental findings and theoretical assessment confirm earlier work: the lattice keeps its fluorite structure with a unit cell parameter that contracts linearly with dopant concentration. The lattice contraction in the (Th1‑xGdx)O2-x/2 system has for the first time been analyzed up to the solubility limit. Similar as for (U1-xGdx)O2.00, the (Th1‑xGdx)O2-x/2 solid solution contracts linearly as a function of dopant concentration but additionally, it develops a superstructure which is closely related to the parent fluorite structure. An excess anion bixbyite trial model is proposed to describe this superstructure."
    Original languageEnglish
    Pages (from-to)135-143
    Number of pages9
    JournalJournal of Nuclear Materials
    Volume467
    Issue number1
    DOIs
    StatePublished - 14 Sep 2015

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