H 65 High-temperature ion transport in La1-xSrxFeO3-delta [] = High-temperature ion transport in La1-xSrxFeO3-delta / Ju. A. Bahteeva, I. A. Leonidov, M. V. Patrakeev, E. B. Mitberg, V. L. Kozhevnikov, K. R. Poeppelmeier // Journal of Solid State Electrochemistry . - 2004. - V. 8, N 9. - С. 578-584 . - ISSN 1432-8488 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ЭЛЕКТРОННАЯ ПРОВОДИМОСТЬ -- ПРОВОДИМОСТЬ ЭЛЕКТРОННАЯ -- La1-xSrxFeO3-ДЕЛЬТА -- ЛАНТАН-СТРОНЦИЕВЫЕ ФЕРРИТЫ -- ФЕРРИТЫ ЛАНТАН-СТРОНЦИЕВЫЕ -- КИСЛОРОДНАЯ ПРОВОДИМОСТЬ -- ПРОВОДИМОСТЬ КИСЛОРОДНАЯ -- ВАКАНСИИ КИСЛОРОДНЫЕ -- КИСЛОРОДНЫЕ ВАКАНСИИ -- ИОННЫЙ ПЕРЕНОС -- ПЕРЕНОС ИОННЫЙ -- ТВЕРДЫЕ РАСТВОРЫ -- РАСТВОРЫ ТВЕРДЫЕ -- ВЫСОКОТЕМПЕРАТУРНАЯ ХИМИЯ -- ХИМИЯ ВЫСОКОТЕМПЕРАТУРНАЯ Аннотация: The conductivity of the entire solid solution La1-xSrxFeO3-delta, where x = 0.2, 0.4, 0.5, 0.7 and 0.9, in the oxygen partial pressure range 10(-19) to 0.5 atm and temperatures between 750 and 950 °C is reported. The analysis of the isothermal pressure dependences of the conductivity reveal that the lanthanum-strontium ferrites can be characterized as mixed ion-electron conductors in the low-oxygen pressure/high-oxygen deficiency limit. The partial contribution to conductivity from oxygen ions increases with strontium content and attains a maximal value at x = 0.5. Further increase in doping results in the development of oxygen vacancy ordering phenomena and deterioration of the conducting properties |
S 89 Structural stability and ion transport in LaSr2Fe1-yCryO8+δ / V. L. Kozhevnikov, I. A. Leonidov, M. V. Patrakeev, J. A. Bahteeva // NATO Science Series II Mathematics, Physics and Chemistry, 2006, Volume 202, Fuel Cell Technologies State and Perspectives. - 2006. - Vol. 202: Fuel Cell Technologies State and Perspectives. - P149-155 : il. - Bibliogr. : p. 155 (2 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): КИСЛОРОДНАЯ ПРОВОДИМОСТЬ -- ЭЛЕКТРОННАЯ ПРОВОДИМОСТЬ -- ФЕРРИТЫ ЛАНТАН-СТРОНЦИЕВЫЕ -- ПЕРОВСКИТЫ Аннотация: Ceramic samples of LaSr2Fe3-yCryO8+δ are characterized with X-ray powder diffraction and total conductivity measurements in the temperature range 750- 950°C and at oxygen partial pressures between 10-22 and 0.5 atm. It is shown that partial replacement of iron for chromium is an effective means to prevent structural transformation at the loss of oxygen. The isothermal ion conductivity is obtained from the analysis of the total conductivity, and it is shown to decrease with the increase in chromium doping to y = 0.6. However further increase in the chromium content to y = 1 results in an increase in the oxygen ion conductivity level. This behavior is explained with a model where the oxygen ions coordinated to chromium are not excluded entirely from the transport mechanism |