Comparison of ZnO-based varistor performance by doping Zn -Sb -O phase and Sb 2 O 3 respectively

In this study, ZnO - Bi 2 O 3 - Cr 2 O 3 - MnO 2 - B 2 O 3 (ZBCMB) varistors were made by doping Zn - Sb - O phase and Sb 2 O 3 phase in low-temperature respectively. Compared with the Sb 2 O 3 doped sample, the breakdown field strength ( E 1mA ) was effectively reduced from 605.36 V/mm to 440.24 V/mm due to the doping of Zn - Sb - O phase. The trend of the nonlinear coefficient alpha is similar for Sb 2 O 3 and Zn - Sb - O doping, although Zn - Sb - O doping leads to a higher alpha = 64. This is due to the fact that the preparation of Zn - Sb - O phase avoids the oxygen vacancy reduction effect caused by the direct reaction of Sb 2 O 3 with Bi 2 O 3 . The doping of Zn - Sb - O effectively increases the concentration of adsorbed oxygen, which has a very large positive effect on the formation of interfacial states and the increase of the potential barrier height.