Cesium incorporation in hollandite-rich multiphasic ceramic waste forms

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• 作者：P. Tumurugoti^a ; ; B.M. Clark^a ; D.J. Edwards^b ; Jake Amoroso^c ; S.K. Sundaram^a
• 关键词：Ceramic waste forms ; Hollandite ; Melt-processing ; SPS ; Cs partitioning ; Microstructure
• 刊名：Journal of Solid State Chemistry
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：246
• 期：Complete
• 页码：107-112
• 全文大小：1654 K
• 卷排序：246

文摘

Hollandite-rich multiphase waste form compositions processed by melt-solidification and spark plasma sintering (SPS) were characterized, compared, and validated for nuclear waste incorporation. Phase identification by x-ray diffraction (XRD) and electron back-scattered diffraction (EBSD) confirmed hollandite as the major phase present in these samples along with perovskite, pyrochlore and zirconolite. Distribution of selected elements observed by wavelength dispersive spectroscopy (WDS) maps indicated that Cs formed a secondary phase during SPS processing, which was considered undesirable. On the other hand, Cs partitioned into the hollandite phase in melt-processed samples. Further analysis of hollandite structure in melt-processed composition by selected area electron diffraction (SAED) revealed ordered arrangement of tunnel ions (Ba/Cs) and vacancies, suggesting efficient Cs incorporation into the lattice.