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Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO_4+?.

ABSTRACT: CeNbO_4+?, a family of oxygen hyperstoichiometry materials with varying oxygen content (CeNbO₄, CeNbO_4.08, CeNbO_4.25, CeNbO_4.33) that shows mixed electronic and oxide ionic conduction, has been known for four decades. However, the oxide ionic transport mechanism has remained unclear due to the unknown atomic structures of CeNbO_4.08 and CeNbO_4.33. Here, we report the complex (3?+?1)D incommensurately modulated structure of CeNbO_4.08, and the supercell structure of CeNbO_4.33 from single nanocrystals by using a three-dimensional electron diffraction technique. Two oxide ion migration events are identified in CeNbO_4.08 and CeNbO_4.25 by molecular dynamics simulations, which was a synergic-cooperation knock-on mechanism involving continuous breaking and reformation of Nb₂O₉ units. However, the excess oxygen in CeNbO_4.33 hardly migrates because of the high concentration and the ordered distribution of the excess oxide ions. The relationship between the structure and oxide ion migration for the whole series of CeNbO_4+? compounds elucidated here provides a direction for the performance optimization of these compounds.

SUBMITTER: Li J

PROVIDER: S-EPMC7506534 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO4+δ.

Li Jian J Pan Fengjuan F Geng Shipeng S Lin Cong C Palatinus Lukas L Allix Mathieu M Kuang Xiaojun X Lin Jianhua J Sun Junliang J

Nature communications 20200921 1

CeNbO4+δ, a family of oxygen hyperstoichiometry materials with varying oxygen content (CeNbO4, CeNbO4.08, CeNbO4.25, CeNbO4.33) that shows mixed electronic and oxide ionic conduction, has been known for four decades. However, the oxide ionic transport mechanism has remained unclear due to the unknown atomic structures of CeNbO4.08 and CeNbO4.33. Here, we report the complex (3 + 1)D incommensurately modulated structure o ...[more]

PMID: 32958759

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Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO_4+?.

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Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO<sub>4+δ</sub>.

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Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO4+?.

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Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO<sub>4+δ</sub>.

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OmicsDI is part of the ELIXIR infrastructure

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Modulated structure determination and ion transport mechanism of oxide-ion conductor CeNbO_4+?.