Impact of impurities on the fabrication and performances of yttrium-doped thoria electrolyte ceramics - Archive ouverte HAL Access content directly
Journal Articles Journal of Nuclear Materials Year : 2022

Impact of impurities on the fabrication and performances of yttrium-doped thoria electrolyte ceramics

(1) , (2) , (2) , (1)
1
2

Abstract

The effect of several impuritites on the life-cycle of yttria-doped thoria electrolyte was evaluated in this study. All the oxide exhibited the single-phase fluorite-type structure expected for such materials, while the variation of the unit cell parameter attested for the incorporation of the impurities in the lattice. Doping with 0.2, 0.5 or 1 wt.% of Al, Si or Zr only slightly affected the morphology of the powders, as well as the microstructure of the pellets obtained after sintering, even if a deleterious effect, leading to the embrittlement of the samples, was observed for high silicon contents. The presence of silicon and zirconium in the ceramic further modified its electrical properties. The grain conductivity was always found to decrease. Impedance spectroscopy also revealed a strong modification of the signal assigned to grain boundaries, which evidenced that impurities partially migrated during the sintering step. Finally, corrosion tests undertaken in liquid sodium at 500°C showed that the pellets were fragilized by the presence of silicon or high zirconium contents, possibly through the formation of Na2MO3 ternary oxides at the grain boundaries. From a general point of view, silicon seems to be the most harmful impurity that should be especially checked during the fabrication processes.
Fichier principal
Vignette du fichier
Impuretés ThY - R1_2_unmarked.pdf (2.35 Mo) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

cea-03517159 , version 1 (07-01-2022)

Licence

Attribution - NonCommercial - NoDerivatives - CC BY 4.0

Identifiers

Cite

Nicolas Clavier, Yanis Cherkaski, Laurent Brissonneau, Nicolas Dacheux. Impact of impurities on the fabrication and performances of yttrium-doped thoria electrolyte ceramics. Journal of Nuclear Materials, 2022, 560, pp.153499. ⟨10.1016/j.jnucmat.2021.153499⟩. ⟨cea-03517159⟩
40 View
20 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More