Aughterson, Robert D.Lumpkin, Gregory R.Smith, Katherine L.Reyes, Massey de losDavis, JoelAvdeev, MaximRidgway, Mark C.Cairney, Julie M.2018-05-240022-3115http://hdl.handle.net/1885/143594We 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.application/pdfhttp://www.sherpa.ac.uk/romeo/issn/0022-3115/..."Author's post-print on open access repository after an embargo period of between 12 months and 48 months" from SHERPA/RoMEO site (as at 24/05/18). This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/In-situ transmission electron microscopyIon irradiationCeramicsCrystallographyLn₂TiO₅201810.1016/j.jnucmat.2018.05.026