Major Effects on Non-ohmic Properties and Aging Stress Behavior of ZPCCD Semiconducting Varistors with Er2O3 Doping Changes

A stress behavior of non-ohmic properties for ZPCCD (ZnO–Pr 1.83 –CoO–Cr 2 O 3 –Dy 2 O 3 ) varistors was investigated for different amounts of the doped Er 2 O 3 . With the amount of the doped Er 2 O 3 increased, the density of the sintered pellet decreased from 5.56 to 5.43 g/cm 3 , and the average grain size decreased from 16.4 to 6.8 μm. With the amount of the doped Er 2 O 3 increased, the breakdown field increased from 1676 to 3939 V/cm, and the non-ohmic coefficient exhibited the fluctuation between 41.4 and 68.1. The varistors doped with 0.25 mol% Er 2 O 3 of exhibited the strongest electrical stability; variation rates for the breakdown field and for the non-ohmic coefficient were 0.1 and − 8.3%, respectively, after application of a strong stress (0.95 E B /150 °C/24 h).