In this study, 1 wt% Bi2O3 (1B), 1 wt% ZnBi2O4 (1BZ), and a composite (a mixture of 1 wt% Bi2O3 and various amounts (1-4 wt%) of ZnBi2O4 ,1B1BZ-1B4BZ) were added to ZnO varistors to investigate the effects of additives on the densification, microstructure, and varistor performance. The results showed that the addition of ZnBi2O4 can lower the densification temperature to about 850oC. When the additive was changed from 1 wt% Bi2O3 to 1 wt% ZnBi2O4, the α value increased from 42 to 54, the breakdown voltage increased from 775 V/mm to 1011 V/mm, and the leakage current decreased to 0.11 μA. Additions of ZnBi2O4 and transition metal cations as donor dopants for the ZnO varistors promote oxygen chemisorption at grain boundaries, resulting in greater α value and lower leakage currents. This suggests the addition of ZnBi2O4 can effectively promote densification and improve the varistor properties of ZnO varistors.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Process Chemistry and Technology
- Surfaces, Coatings and Films
- Materials Chemistry