Ionic conductivity and thermal expansion of anion-deficient Sr11Mo4O23 perovskite
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Date
2020-07-07
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Publisher
Springer Nature
Abstract
Transport properties of perovskite-type Sr11Mo4O23 and composite Sr11Mo4O23 - 1 wt% Al2O3 were studied at 400–1300 K in the oxygen partial pressure range from 0.21 down to 10−19 atm. The electromotive force and faradaic efficiency measurements, in combination with the energy-dispersive spectroscopy of the fractured electrochemical cells, unambiguously showed prevailing role of the oxygen ionic conductivity under oxidizing conditions. At temperatures above 600 K, protonic and cationic transport can be neglected. The oxygen ion transference numbers vary in the range of 0.95–1.00 at 973–1223 K. At temperatures lower than 550 K, the total conductivity of Sr11Mo4O23 - 1 wt% Al2O3 composite measured by impedance spectroscopy tends to increase in wet atmospheres, thus indicating that hydration and protonic transport become significant. Reducing oxygen partial pressure below 10−10–10−9 atm leads to a significant increase in the n-type electronic conduction. The average thermal expansion coefficients in oxidizing atmospheres are (14.3–15.0) × 10−6 K−1 at 340–740 K and (18.3–19.2) × 10−6 K−1 at 870–1370 K. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature
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Keywords
Thermal expansion, Electrolytes, Oxides, Strontium compounds, Molybdates, Ionic conductivity, Oxygen, Electric conductors, Impedance
Citation
Kharton, V. V., Tsipis, E. V., Kolotygin, V. A., Avdeev, M., & Kennedy, B. J. (2020). Ionic conductivity and thermal expansion of anion-deficient Sr11Mo4O23 perovskite. Journal of Solid State Electrochemistry, 24, 2943–2951. doi:10.1007/s10008-020-04688-x