Abstract In this study, the effect of strontium titanate (SrTiO 3 ) doping on the microstructural evolution and electrical characteristics of zinc oxide (ZnO) varistors is investigated. The ZnO-SrTiO 3 ceramic was synthesized using a two-stage sintering technique. Microstructural analysis using X-Ray Diffraction (XRD) reveals the formation of Zn 2 TiO 4 spinel phase, while scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis confirm the segregation of Sr-rich secondary phases at the grain boundaries and triple points. The microstructure and densification were significantly enhanced at the optimum SrTiO 3 concentration, thereby improving the electrical properties of the fabricated varistor, with the nonlinear coefficient (α) increasing to 5.49 and the leakage current density ( J L ) decreasing to 298 μA/cm 2 . This investigation provides a deeper understanding of dopants’ influence on ZnO varistors, thereby facilitating the development of more effective and reliable surge protective devices, especially for low-voltage applications.
Daud et al. (Sun,) studied this question.