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Relationship between the Structure and Transport Properties in the Ce1−xLaxO2−x/2 System Zamudio-García, Javier Porras-Vázquez, José Manuel Canales-Vázquez, J. Cabeza-Díaz, Aurelio Losilla, Enrique R. Marrero-López, David Pilas de combustible Catalizadores La-doped CeO2 materials have been widely investigated for potential applications in different high-temperature electrochemical devices, such as fuel cells and ceramic membranes for hydrogen production. However, the crystal structure is still controversial, and different models based on fluorite, pyrochlore, and/or type-C structures have been considered, depending on the lanthanum content and synthesis method used. In this work, an exhaustive structural analysis of the Ce1−xLaxO2−x/2 system (0.2 < x ≤ 0.7) is performed with different techniques. The average crystal structure, studied by conventional X-ray diffraction, could be considered to be a disordered fluorite; however, the local structure, examined by electron diffraction and Raman spectroscopy, reveals a biphasic mixture of fluorite and C-type phases. The thermal and electrical properties demonstrate that the materials with x ≥ 0.4 are oxide ion proton conductors in an oxidizing atmosphere and mixed ionic electronic conductors in a reducing atmosphere. The water uptake and proton conductivity increase gradually with the increase in La content, suggesting that the formation of the C-type phase is responsible for the proton conduction in these materials. 2021-02-25T12:07:46Z 2021-02-25T12:07:46Z 2021-02-24 2019-06-25 journal article Zamudio-García, J., Porras-Vázquez, J., Canales-Vázquez, J., Cabeza, A., Losilla, E., & Marrero-López, D. (2019). Relationship between the Structure and Transport Properties in the Ce1–xLaxO2–x/2 System. Inorganic Chemistry, 58(14), 9368–9377. https://doi.org/10.1021/acs.inorgchem.9b01104 https://hdl.handle.net/10630/20991 10.1021/acs.inorgchem.9b01104 eng open access American Chemical Society