Oxygen Dynamics and Diffusion Mechanism in Intergrowth Bi2WO6-Bi3TiNbO9 Ferroelectrics.

Dielectric and impedance spectroscopies were employed to study intergrowth Bi5TiNbWO15 ferroelectrics. It was observed one ferroelectric phase transition at 1096 K and two dielectric relaxation processes involving bulk and grain boundary effects. It was also found that the bulk response within the material is of localized relaxation process, the temperature dependence of the relaxation strength is analogous to the Curie-Weiss law and the interactions between the oxygen vacancies in the bulk material follow the traditional point defects relaxation theory. Based on the analysis of the crystal structure, a short range diffusion mechanism of oxygen ions coordinating A sites was proposed. [ABSTRACT FROM AUTHOR]