Mossbauer spectroscopic study of high-temperature proton-conducting Ba2SnY1-x Fe x O6-δ oxides

High-temperature proton-conducting Ba2SnY1 - x Fe (x) O6 - delta oxides are studied by Mossbauer spectroscopy on Sn-119 and Fe-57 isotopes. For the perovskite structure, the possible states of anionic vacancies are discussed as a function of the nature of the nearest small cations. It is concluded that the energy of formation of a cation-vacancy-cation defect depends on the overall concentration of vacancies in the compound. As the result, with the increase in the water content in the Ba2SnYO6 - delta compound, the equilibrium shifts to the tin-vacancy-tin state.