Oxygen intercalation in Ruddlesden-Popper type Sr3LaFe3O10-δ

• Autor(a) principal: Tsipis, Ekaterina V.
• Data de Publicação: 2018
• Outros Autores: Naumovich, Eugene N., Patrakeev, Mikhail V., Kharton, Vladislav V.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/37458
• topic: Layered ferrites; Defects; Simulation and modelling; Coulometric titration; Thermal analysis; Ceramics

The oxygen nonstoichiometry of Ruddlesden-Popper type Sr3LaFe3O10-δ, a promising parent material for mixed-conducting electrodes and membranes, was studied in the oxygen partial pressure range from 10−24 to 0.5 atm at 973–1223 K by coulometric titration and thermogravimetry. The p(O2)-T-δ diagram can be described using a statistical thermodynamic model relating the non-ideal behavior in oxidizing and strongly reducing atmospheres to the coulombic interaction between oxygen vacancies and electronic charge carriers. The results confirm a strong energetic affinity of anion vacancies to the central perovskite-like layers of the Ruddlesden-Popper structure, whilst the difference between crystallographic iron sites has no significant effects on the oxygen intercalation thermodynamics at elevated temperatures. No indications of long-range ordering in the oxygen sublattice were observed.