Abstract: For the first time, manganese bismuth niobates doped with Li and Ru atoms have been synthesized and investigated. The compositions Bi1.5-xLixMn0.75Nb1.5-yRuyO7‒δ (x = 0, 0.1, 0.2; y = 0-0.5) are characterized by the pyrochlore structure. The distribution of dopants in the structure was determined by structural analysis and measurement of pycnometric density values. From the theoretical calculation and experimental optical data, the band gap (Eg) gradually decrease with Ru concentration. The mixed electron and oxygen conductivity was determined for the ceramics. Oxygen transport was investigated by temperature-programmed isotope exchange of oxygen (TPIE) with C18O2 in a flow reactor and by experiments using an ion-blocked electrode. Oxygen diffusion activation starts at 200-250 °C for Ru-free compositions and at 50 °C for Ru-reach compounds, with oxygen transport numbers corresponding to tion = 0.2 and 0.7-0.8 at 400 °C, respectively. Electronic conductivity, moderate oxygen mobility (D* ∼ 10-12–10-11 cm2/s at 700 °C), chemical compatibility with La0.7Sr0.3MnO3 perovskite (up to 800 °C) make the obtained pyrochlores a potential component of composite cathode material for intermediate temperature SOFCs.

Cite: Koroleva M.S. , Eremeev N.F. , Sadovskaya E.M. , Sadykov V.A. , Piir I.V.
Synthesis, Optical Properties, and Oxide Ionic Transport Features in Mn-Li-, Mn-Ru-, Mn-Ru-Li-codoped Bismuth Niobate Pyrochlores
Ceramics International. 2025. DOI: 10.1016/j.ceramint.2024.12.412 Scopus OpenAlex

Dates:

Submitted:	Oct 31, 2024
Accepted:	Dec 24, 2024
Published online:	Dec 26, 2024

Identifiers:

Scopus:	2-s2.0-85213970233
OpenAlex:	W4405825683

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