Effect of Er_2O_3 on the Microstructure and Electrical Properties of WO_3 Capacitor-varistor Ceramics

摘要

WO_3-based capacitor-varistor ceramics doped with Er_2O_3 were prepared and the microstructures and nonlinear electrical properties were investigated. The results show that there exist second phase Er_(10)W_2O_(21) on the surface of WO_3 grains. Doping Er_2O_3 in WO_3 ceramic can inhibit the grain growth. A small quantity of Er_2O_3 can significantly improve nonlinear properties of the samples. The permittivity of doped samples was higher than that of the undoped, and the high permittivity makes Er_2O_3-doped WO3 ceramics be applicable as a kind of capacitor-varistor materials.