The ion-irradiation tolerance of the pyrochlore to fluorite Ho(x)Yb(2-x)TiO5 and Er2TiO5 compounds: a TEM comparative study using both in-situ and bulk ex-situ irradiation approaches
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Date
2018-08-15
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Elsevier
Abstract
We refine the crystal structures of a systematic series of compounds with the general composition Ho(x)Yb(2-x)TiO5 (x = 2, 1.6, 1.2, 1, 0.8, 0.4, 0) and Er2TiO5 and find a transition from defect-pyrochlore to defect-fluorite structure with increasing ytterbium content, decreasing lanthanide radius. Short-range structure modulations consisting of pyrochlore-like nano-domains are systematically characterised using transmission electron microscopy. We test the Kr2+ 1 MeV ion-irradiation response of Ho2TiO5, HoYbTiO5, Yb2TiO5, and Er2TiO5, via the crystalline to amorphous transition observed by using the in-situ TEM approach. The critical dose of amorphisation, Dc, was measured at various temperatures and used to calculate the critical temperature for maintaining crystallinity, Tc. A trend of lower Tc values with decreasing lanthanide radius is found. We describe a new approach for determining Tc values using cross-sectional TEM analysis of ex-situ bulk irradiated, 1 MeV Se+, samples; Ho2TiO5, HoYbTiO5 and Yb2TiO5. The results of Dc and Tc values using the two approaches vary; however the trends across the sample system remain the same. © 2018 Published by Elsevier B.V.
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Keywords
Transmission electron microscopy, Irradiation, Ceramics, Crystallography, Pyrochlore, Ytterbium, Rare earths, Crystal structure
Citation
Aughterson, R. D., Lumpkin, G. R., Smith, K. L., de los Reyes, M., Davis, J., Avdeev, M., Ridgway, M. C., & Cairney, J. M. (2018). The ion-irradiation tolerance of the pyrochlore to fluorite Ho(x)Yb(2-x)TiO5 and Er2TiO5 compounds: a TEM comparative study using both in-situ and bulk ex-situ irradiation approaches. Journal of Nuclear Materials, 507, 316-326, doi:10.1016/j.jnucmat.2018.05.026