The effect of NiO on the microstructural properties of ZnO

Keywords: ZnO varistors, Microstructural changes, Grain growth. In this study, the investigations of the effect of doping NiO on the microstructure of ZnO is aimed. For this aim, Ni(OH2) was initially added to ZnO with 1wt.%, 2wt.%, 3wt.%, 4 wt.% and these were mixed in wet condition.Then this power mixture was dried in etuv at 110oC and milled.After that these pressed to compacts having 10 mm diameter and sintered at 1000°C, 1100°C, 1200°C and 1300°C during 1, 2, 3, 5 hours. Some characterization procedures were applied to sintered specimens. XRD, TG and DTA analyses to the powder mixtures before sintering and also, the XRD, SEM-EDS analyses to the sintered samples were performed. Afterwards, the bulk concentrations and activation energies were calculated with the determination of the grain dimensions from the optical photographs of the samples. By doing so, the effect of doping NiO on the microstructure of ZnO has been evaluated.