Вид документа : Статья из журнала Шифр издания : 54/O-97 Автор(ы) : Patrakeev M. V., Leonidov I. A., Mitberg E. B., Lakhtin A. A., Vasiliev V. G., Kozhevnikov V. L., Poeppelmeier K. R. Заглавие : Oxygen Thermodynamics and Ion Conductivity in the Solid Solution La .xSrxCoO3-delta at Large Strontium Content Место публикации : Ionics. - 1999. - Vol. 5, № 5-6. - С. P. 444-449: il. Примечания : Bibliogr. : p. 448-449 (32 ref.) ББК : 54 Предметные рубрики: ХИМИЧЕСКИЕ НАУКИ Ключевые слова (''Своб.индексиров.''): термодинамика--ионная проводимость--растворы твердые--стронций--лантан--кобальт Аннотация: The equilibrium oxygen content was measured in the model system and important oxygen permeable material Lal.xSrxCoO3-delta, where x = 0.6, in the temperature range 650-900 ~ and oxygen partial pressure range between 10 .5 and 1 atm. The data were utilized to obtain changes in the partial entropy and enthalpy of oxygen in the solid as a function of the oxygen content. It is shown that the initially cubic perovskite undergoes to a phase transition to a tetragonal structure at delta 0.3. The oxygen permeation of L0.4Sr0.6CoO3-delta at 700-900 C is found to be controlled by bulk solid state processes. The activation energy equals about 0.8 eV at high oxygen pressure and small oxygen nonstoichiometry. Increasing oxygen deficiency results in a rapid increase in the activation energy. In combination with thermodynamic data, these changes can be explained as resulting from the intrinsic, spatial inhomogeneouty in oxygen vacancy distribution which varies both with temperature and oxygen nonstoichiometry. It is shown that, when the oxygen deficiency increases at constant temperature, the oxygen vacancies form locally ordered microdomains (clusters), which eventually results in a transition of the cubic perovskite structure to the tetragonal structure. The oxygen ion conductivity depends strongly on the development of the ordering Доп.точки доступа: Patrakeev, M. V.; Патракеев Михаил Валентинович; Leonidov, I. A.; Леонидов Илья Аркадьевич; Mitberg, E. B.; Lakhtin, A. A.; Лахтин Андрей Анатольевич; Vasiliev, V. G.; Васильев Виктор Георгиевич; Kozhevnikov, V. L.; Кожевников Виктор Леонидович; Poeppelmeier, K. R.