What are the properties and application characteristics of zinc oxide ceramics

       Zinc oxide (ZnO) ceramic is a white powder with a typical hexagonal crystal structure. This crystal is very stable and does not undergo phase change at high temperature until its decomposition temperature. The melting point is 1975 degrees Celsius, and the thermal expansion coefficient is 6.77X10-6K-1 (25~1000℃)

     Due to the large gap in the crystal structure, Zn can easily enter the gap or under the condition of high oxygen partial pressure, zinc oxide decomposes to form interstitial Zn atoms, so that zinc oxide has been ionized at room temperature and has n-type semiconductor characteristics, called is the n-type conductance due to intrinsic defects. Overdoping (such as adding AI and Ga) or controlling the processing atmosphere can significantly affect the conductivity of zinc oxide and achieve controllability. Its characteristic is that when the applied voltage exceeds a certain value, its current increases geometrically, and the resistance value of the varistor decreases sharply. This feature is used in components such as power arresters to protect the safety of power system equipment during thunderstorms.