Вид документа : Статья из журнала Шифр издания : 54/P 45 Автор(ы) : Kharton V. V., Shaulo A. L., Viskup A. P., Avdeev M., Yaremchenko A. A., Patrakeev M. V., Kurbakov A. I., Naumovich E. N., Marques F. M. B. Заглавие : Perovskite-like system (Sr, La)(Fe, Ga)O3-delta: structure and ionic transport under oxidizing conditions Место публикации : Solid State Ionics. - 2002. - V. 150, N 3-4. - С. 229-243. - ISSN 0167-2738. - ISSN 0167-2738 Примечания : Bibliogr.: p. 243 (50 ref.) ББК : 54 Предметные рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The maximum solid solubility of gallium in the perovskite-type La1-xSrxFe1-yGayO3-delta (x = 0.40 - 0.80; y = 0-0.60) was found to vary in the approximate range y = 0.25-0.45, decreasing when x increases. Crystal lattice of the perovskite phases, formed in atmospheric air, was studied by X-ray diffraction (XRD) and neutron diffraction and identified as cubic. Doping with Ga results in increasing unit cell volume, while the thermal expansion and total conductivity of (La, Sr)(Fe, Ga)O3-delta in air decrease with gallium additions. The average thermal expansion coefficients (TECs) are in the range (11.7-16.0) x 10(-6)K(-1) at 300-800 K and (19.3-26.7) x 10(-6)K(-1) at 800-1100 K. At oxygen partial pressures close to atmospheric air, the oxygen permeation fluxes through La1-xSrxFe1-yGayO3-delta (x = 0.7-0.8; y = 0.2-0.4) membranes are determined by the bulk ambipolar conductivity; the limiting effect of the oxygen surface exchange was found negligible. Decreasing strontium and gallium concentrations leads to a greater role of the exchange processes. As for many other perovskite systems, the oxygen ionic conductivity of La1-xSrxFe1-yGayO3-delta increases with strontium content up to x = 0.70 and decreases on further doping, probably due to association of oxygen vacancies. Incorporation of moderate amounts of gallium into the B sublattice results in increasing structural disorder, higher ionic conductivity at temperature below 1170 K, and lower activation energy for the ionic transport Доп.точки доступа: Kharton, V. V.; Shaulo, A. L.; Viskup, A. P.; Avdeev, M.; Yaremchenko, A. A.; Patrakeev, M. V.; Патракеев Михаил Валентинович; Kurbakov, A. I.; Naumovich, E. N.; Marques, F. M. B.