Probing Dopant Size Effects on Defect Clustering and Vacancy Ordering in Lanthanide-doped Ceria.

ABSTRACT: Dopant size is known to influence oxygen vacancy-mediated conduction pathways and ionic conductivity in doped ceria, yet the underlying atomic-scale mechanisms remain unclear. Here, we combine neutron total scattering and large-scale atomistic simulations to analyze the local defect structures of two representative doped ceria systems: Ce_0.8Gd_0.2O_1.9 (GDC) and Ce_0.8Nd_0.2O_1.9 (NDC). The local structure of GDC, a commercially used ion conductor, is investigated for the first time using neutron total scattering on ¹⁶⁰Gd-enriched samples. GDC exhibits fewer defect clusters, with vacancy pairs preferentially aligned along ⟨111⟩ and ⟨110⟩ directions while disfavoring ⟨100⟩ direction within the cubic fluorite structure.

SUBMITTER: Ming J 

PROVIDER: S-EPMC12412159 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature