Influence of Zr-doping on the structure and transport properties of rare earth high-entropy oxides
In: JPhys Energy, Jg. 6 (2024), Heft 3, S. 035001-35001
Online
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Zugriff:
Fluorite-type ceria-based ceramics are well established as oxygen ion conductors due to their high conductivity, superseding state-of-the-art electrolytes such as yttria-stabilized zirconia. However, at a specific temperature and oxygen partial pressure they occasionally exhibit electronic conduction attributed to polaron hopping via multivalent cations (e.g. Pr and Ce). (Ce, La, Pr, Sm, Y)O _2− _δ is a high-entropy oxide with a fluorite-type structure, featuring low concentrations of multivalent cations that could potentially mitigate polaron hopping. However, (Ce, La, Pr, Sm, Y)O _2− _δ undergoes a structural transition to the bixbyite-type structure above 1000 °C. In this study, we introduce Zr doping into (Ce, La, Pr, Sm, Y)O _2− _δ to hinder the structural transition at elevated temperatures. Indeed, the fluorite structure at elevated temperatures is stabilized at approximately 10 at.% Zr doping. The total conductivity initially increases with doping, peaking at 5 at.% Zr doping, and subsequently decreases with further doping. Interestingly, electronic conductivity in (Ce, La, Pr, Sm, Y) _1− _x Zr _x O _2− _δ under oxidizing atmospheres is not significant and is lowest at 8 at.% Zr. These results suggest that ceria-based high-entropy oxides can serve as oxygen ion conductors with a significantly reduced electronic contribution. This work paves the way for new compositionally complex electrolytes as well as protective coatings for solid oxide fuel cells.
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Influence of Zr-doping on the structure and transport properties of rare earth high-entropy oxides
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Autor/in / Beteiligte Person: | Mohana V Kante ; Ajai R Lakshmi Nilayam ; Kreka, Kosova ; Hahn, Horst ; Subramshu S Bhattacharya ; Velasco, Leonardo ; Tarancón, Albert ; Kübel, Christian ; Schweidler, Simon ; Botros, Miriam |
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Zeitschrift: | JPhys Energy, Jg. 6 (2024), Heft 3, S. 035001-35001 |
Veröffentlichung: | IOP Publishing, 2024 |
Medientyp: | academicJournal |
ISSN: | 2515-7655 (print) |
DOI: | 10.1088/2515-7655/ad423c |
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