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Communication Dans Un Congrès Année : 2020

Global and Local Structural Modifications in Swift Heavy Ion Irradiated Sc4Hf3O12

Résumé

Aliovalent cation-doped fluorite oxide structures are ideal candidates to understand phase stability and their transformation pathways under radiation. These systems are relevant models for nuclear fuels and waste forms. Sc4Hf3O12 is a delta phase crystallising in a trigonal symmetry. This and other A4B3O12-type systems were observed to transform into a long-range defect fluorite phase upon low energy ion irradiations. On one instance Sc4Hf3O12 was also observed to partially turn into a bixbyite phase, however, the reasons behind this were never clearly understood. Thus, in the present study, swift heavy ion irradiated Sc4Hf3O12 was investigated as a function of fluence using x-ray diffraction. Structural parameters obtained from quantitative Rietveld analysis reveal that, while the long-range average structure develops into a defect fluorite, the local structure tends to convert into a bixbyite-like arrangement. Similarities in the polyhedra suggest this bixbyite-related local phase is a metastable system that effectively provides radiation resistance by creating large numbers of bixbyite-like replicas within an aristotype fluorite mesocrystal.
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Dates et versions

hal-03194977 , version 1 (09-04-2021)

Identifiants

  • HAL Id : hal-03194977 , version 1

Citer

Maulik Patel, Kurt E. Sickafus, Gianguido Baldinozzi. Global and Local Structural Modifications in Swift Heavy Ion Irradiated Sc4Hf3O12. Defects, Order and Disorder in Structural and Functional Fluorite-Related Compounds (Symp CT05), Materials Research Society (MRS), Nov 2020, Boston (Virtual), United States. ⟨hal-03194977⟩
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