Influences of Donor Additives on Properties of TiO2-Based Varistor
In this paper, the TiO2-based varistor ceramics added different donor additives were prepared and their propreties had been compared. The effects of added methods and added amounts of V2O5 (Nb2O5, or Ta2O5) on the microstructure, dielectric and varistor properties of TiO2 double functional ceramics were investigated. The ceramic phase and the microstructure of the disks were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The frequency dependences of the samples capacitance (C), the dielectric loss (tanδ) were determined on LCR meter, and the varistor voltage V1mA was measured by using FC-2G meter. It is found that the proper amount of V2O5, Nb2O5 or Ta2O5 additves can promote the growth of the crystal and the formation of the grain boundary layer at a different extent. Meanwhile, the proper addition amount can increases the nonlinear exponent and the dielectric constant, but decreases the breakdown voltage. It can also improve the sintering properties of the samples.
Wei Pan and Jianghong Gong
M. Zou et al., "Influences of Donor Additives on Properties of TiO2-Based Varistor ", Advanced Materials Research, Vols. 105-106, pp. 320-323, 2010