Structural and electrical properties of ZnO and SiO2 doped ZnO powder for varistor application

Pure zinc oxide (ZnO) and silica (SiO2) doped ZnO nanopowders have been prepared using solid state method. SiO2 were doped into ZnO at different weight percentage 1 and 3 wt.%. The structural and electrical properties of ZnO and SiO2 doped ZnO powder have been characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and electro source meter. From the results, the XRD pattern were compatible with ZnO phase structure. Based on the SEM images, the grain size of ZnO varistor is increased when doped with SiO2. The obtained value of nonlinear coefficient (α) of undoped ZnO sample is low compared to SiO2 doped ZnO varistor. The, α value is increased as the content of SiO2 doped increases. The maximum value of α is at 3 wt.% of SiO2 doped ZnO which is 1.734 that might be can enhanced the performance of varistor. Thus, the properties of ZnO varistor can be improved when doped with SiO2.