Temperature-activation mechanism of the temperature dependence of the dielectric constant of ferroelectric ceramics PZT

The theoretical possibility of the temperature-activation process of the temperature dependence of the dielectric constant of samples of ferroelectric ceramics lead zirconate titanate (PZT) at temperatures below the Curie point is considered. The model takes into account the 180 degrees motion of the domain wall, which is located in the potential well. The values of activation energies ( similar to 0.01, 0.1, 1 eV) were obtained from the experimental dependences of the logarithm of the dielectric constant on the reciprocal temperature. This is associated with three processes: initial vibrations of domain walls; separation of domain walls (DWs) from oxygen vacancies; the motion of DWs as a result of the motion of oxygen vacancies.