Oxygen-vacancy-mediated dielectric property in perovskite Eu0.5Ba0.5TiO3-δ epitaxial thin films

Dielectric relaxation in ABO(3) perovskite oxides can result from many different charge carrier-related phenomena. Despite a strong understanding of dielectric relaxations, a detailed investigation of the relationship between the content of oxygen vacancies (V-o) and dielectric relaxation has not been performed in perovskite oxide films. In this work, we report a systematic investigation of the influence of the V-o concentration on the dielectric relaxation of Eu0.5Ba0.5TiO3-delta epitaxial thin films. Nuclear resonance backscattering spectrometry was used to directly measure the oxygen con- centration in Eu0.5Ba0.5TiO3-delta films. We found that dipolar defects created by V-o interact with the off-centered Ti ions, which results in the dielectric relaxation in Eu0.5Ba0.5TiO3-delta films. Activation energy gradually increases with the increasing content of V-o. The present work significantly extends our understanding of relaxation properties in oxide films. Published by AIP Publishing.