The leakage current of the tungsten oxide ceramic varistor under the action of the applied voltage is a decreasing process with time. This shows that the grain boundary barrier model of tungsten oxide varistors is different from conventional varistors such as zinc oxide.

Researchers have found that ultraviolet and visible light can provide energy for the surface chemical reaction of tungsten oxide gas-sensitive materials, thereby accelerating the rate of chemical reactions, thereby improving its gas-sensing properties. The study found that ultraviolet light affects the gas-sensitive properties of tungsten oxide gas mainly through two aspects:

In 1994, it was first discovered that doped tungsten oxide varistors have varistor properties. Due to the lower varistor voltage, the varistor characteristics of tungsten oxide attract attention. Later, the effects of alumina and other dopants on the pressure sensitive properties were reported. However, the varistor characteristics of tungsten oxide varistor ceramics are extremely unstable, such as poor reproducibility of electrical behavior and negative resistance behavior, and the nonlinear coefficient is much smaller than that of zinc oxide. Therefore, there are few reports on tungsten oxide varistor ceramics in foreign countries, but there are many reports on the use of tungsten oxide varistors in gas sensors.

Because of the larger radius of oxygen atoms, poor mobility. Therefore, in the sintering process of oxide ceramics, the transmission rate of oxygen atoms determines the sintering performance of tungsten oxide ceramics.

The graph below shows the volt-ampere characteristics of tungsten oxide ceramics sintered at different holding temperatures. The electrical non-linear behavior of varistors typically occurs at current densities in the region of 1-10 mA. From the figure we can see that at 1050 ℃ 1100 ℃ and insulation for two hours of tungsten oxide ceramics, in the current density of 1-10mA region has a non-linear volt-ampere curve. That is, the pressure sensitive characteristics are exhibited.