The effect of sintering temperature on varistor properties of (Pr, Co, Cr, Y, Al)-doped ZnO ceramics

Abstract The effect of sintering temperature on varistor properties of (Pr, Co, Cr, Y, Al)-doped ZnO ceramics was investigated in the range of 1280–1350 °C. The increase of sintering temperature increased the average grain size (4.8–12.9 μm), whereas the sintered density was not nearly affected by sintering temperature. The breakdown field decreased over a wide range from 4610 to 1513 V/cm with the increase of sintering temperature. The nonlinear coefficient of this system was nearly constant in the range of 44–47 regardless of sintering temperature. The donor density decreased in the range of 1.51–1.32 × 10 18 /cm 3 and the barrier height decreased from 1.40 to 0.92 eV with the increase of sintering temperature.