Influence of Process Variables on Microstructure and V‐I Characteristics of Multicomponent ZnO‐Based Nonlinear Resistors

Studies have been made of the effect of process variables such as calcination, initial particle size, and postsinterin on density, microstructure, V‐I characteri stics, and energy ‐handling capability of a ZnO‐based composite: 87.325 wt% ZuO + 0.1% Nb 2 O 5 + 3.5% Sb 2 O 5 + 6% Bi 2 O 3 + 0.55% CoO + 0.7% MnO 2 + 0.9% Cr 2 O 3 + 0.9% NiO + 0.025% Al(NO 3 ) 3 . The nonlinear characteristics were found to be improved by the calcination of a ZnO + Nb 2 O 5 mixture at 1200°C for 1h. The postsintering heat treatment was found to rejuvenate V‐I characteristics of the degraded sample to a greater extent. Further, the postsintered sample containing Nb 2 O 5 , prepared by using a calcined charge of particle size around 1 μm, was found to possess better V‐I characteristics and energy‐handling capability compared to the samples prepared without the calcination step.