Grain Boundary Defect Chemistry of Acceptor-Doped Titanates: High Field Effects

The field enhanced average conductivity in grain boundary space charge depletion layers in acceptor-doped SrTiO₃ ceramics was investigated by impedance analysis in the time domain. The dependence of the grain boundary conductivity on the acceptor concentration, the temperature and the field dependence are discussed and interpreted in terms of a Schottky diffusion model combined with the influence of accumulated oxygen vacancies at the GB interface.