Abstract

WO₃-based varistors with added Na₂O and B₂O₃ were synthesized by the solid-state reaction. The undoped and B₂O₃-doped WO₃ ceramics exhibited weak nonlinear I–V characteristics. The nonlinear I–V characteristics of the ceramics increased slightly after the addition of Na₂O and more significantly after the addition of Na₂O and B₂O₃. The nonlinearity coefficients α of the WO₃, Na_0.005WO₃, and Na_0.005WO₃–5 wt % B₂O₃ ceramics were 1.86, 2.03, and 5.22, respectively. The breakdown voltages of the WO₃, Na_0.005WO_3, and Na_0.005WO₃–5 wt % B₂O₃ ceramics were 1.56, 6.05, and 12.42 V/cm, respectively. The dielectric constant and the dielectric loss of the Na_0.005WO₃–5 wt % B₂O₃ ceramic were ~50–150 and less than 0.3, respectively, for frequencies ranging from 1 to 1000 kHz.

This work is licensed under a Creative Commons Attribution 4.0 License.