Blackburn, L.R., Sun, S.-K., Lawson, S.M. et al. (6 more authors) (2020) Synthesis and characterisation of Ca1-xCexZrTi2-2xCr2xO7: Analogue zirconolite wasteform for the immobilisation of stockpiled UK plutonium. Journal of the European Ceramic Society, 40 (15). pp. 5909-5919. ISSN 0955-2219
Abstract
A series of Ca1-xCexZrTi2-2xCr2xO7 zirconolite ceramics (0 ≤ x ≤ 0.35) were reactively sintered in air at 1350 °C for 20 h. Single phase zirconolite-2M was formed for x ≤ 0.15, with Cr2O3 and an undesirable Ce-bearing perovskite phase present above x = 0.20. Electron diffraction analysis confirmed that the zirconolite-2M polytype was maintained over the solid solution. X-ray absorption near edge structure (XANES) data determined that between 10–20% Ce was speciated as Ce3+, and Cr was present uniformly as Cr3+ with near edge features consistent with occupation of octahedral sites within the zirconolite-2M structure. A sample corresponding to x = 0.20 was processed by reactive spark plasma sintering (RSPS), with a rapid processing time of less than 1 h. XANES data confirmed complete reduction to Ce3+ during RSPS, promoting the formation of a Ce-bearing perovskite, comprising 19.3 ± 0.4 wt. % of the phase assemblage.
Metadata
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Copyright, Publisher and Additional Information: | © 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/BY/4.0/). | ||||||||||
Keywords: | Zirconolite; Immobilisation; Plutonium; Surrogate; Wasteform | ||||||||||
Dates: |
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Institution: | The University of Sheffield | ||||||||||
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) | ||||||||||
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Depositing User: | Symplectic Sheffield | ||||||||||
Date Deposited: | 08 Jul 2020 15:52 | ||||||||||
Last Modified: | 20 Jan 2022 09:28 | ||||||||||
Status: | Published | ||||||||||
Publisher: | Elsevier BV | ||||||||||
Refereed: | Yes | ||||||||||
Identification Number: | https://doi.org/10.1016/j.jeurceramsoc.2020.05.066 |