Proton conduction in thin film yttrium-doped barium zirconate

The proton conductivity of yttrium-doped barium zirconate (BYZ) films epitaxially grown on MgO(100) has been studied in the range of 140–290°C as a function of film thickness (60–670nm) in relation to their crystal and morphological structure at the nanoscale. Highly textured 60nm BYZ film epitaxially grown on MgO(100) showed high ionic conductivity, close to its bulk value. In contrast, thicker polycrystalline samples with rougher surfaces, caused by grain boundary formation, exhibited lower conductivity.