Electrical properties of Pr6O11-doped WO3 capacitor–varistor ceramics

The microstructure and electrical properties of Pr6O11-doped WO3 ceramics were investigated. Results showed that the breakdown voltage of doped samples was lower than that of the undoped. The dielectric constant of doped samples was higher than that of the undoped, and the high dielectric constant made Pr6O11-doped WO3 ceramics to be applicable as a kind of capacitor–varistor materials. A small content of Pr6O11 could significantly improve nonlinear properties of the samples. The WO3–0.03 mol% Pr6O11 obtained a large nonlinear coefficient of 3.8, a low breakdown voltage of 8.8 V/mm, and a high dielectric constant of 7.69 × 104 at 1 kHz. The defects theory was introduced to explain the nonlinear electrical behavior of Pr6O11-doped WO3 ceramics.