Oxygen-vacancy-related relaxation and conduction behavior in (Pb1-xBax)(Zr0.95Ti0.05)O3 ceramics

(Pb1-xBax)(Zr0.95Ti0.05)O3 (x = 0, 0.025, 0.05, 0.075 and 0.1) ceramics were prepared via a solid-state reaction route. Low-frequency (20 ∼ 2 × 107 Hz) dielectric properties were investigated in the temperature region of 25-650 °C. Ba2+ doping can slightly reduce the phase transition temperature of ferroelectric to paraelectric. The dielectric diffuse anomaly in the dielectric relaxation was found in the high temperature region of 400-650 °C. Activation energy, calculated from the impedance and conductivity data of samples, suggests that the dielectric relaxation is due to oxygen vacancies generated during the sintering process. Ba2+ doping can reduce significantly the concentration of oxygen vacancies, and slightly enhance activation energy for the migration of oxygen vacancies. Results of activation energy calculated from impedance and conductance suggest that the dielectric relaxation is due to the short-range hopping of oxygen vacancies, and the conduction due to the movement of doubly-ionized oxygen vacancies