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
Date
2018
Authors
Aughterson, Robert D.
Lumpkin, Gregory R.
Smith, Katherine L.
Reyes, Massey de los
Davis, Joel
Avdeev, Maxim
Ridgway, Mark C.
Cairney, Julie M.
Journal Title
Journal ISSN
Volume Title
Publisher
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.
Description
Keywords
In-situ transmission electron microscopy, Ion irradiation, Ceramics, Crystallography, Ln₂TiO₅
Citation
Collections
Source
Journal of Nuclear Materials
Type
Journal article
Book Title
Entity type
Access Statement
Open Access
License Rights
DOI
10.1016/j.jnucmat.2018.05.026