Synthesis and analysis of structural, dielectric, and thermistor behaviour of zinc ferrite

Abstract

This paper discusses the synthesis, dielectric properties, and applications of ZnFe2O4 for the thermistor. A high-temperature solid-state reaction method is used to create the polycrystalline ZnFe2O4 sample. The X-ray diffraction study identified the single spinel Cubic phase formation at room temperature without any impurities. The broadening of the XRD peaks determined structural parameters including crystallite size, microstrain, dislocation density, and percentage crystallinity which confirms the lower number of lattice defects in the ferrite. The dielectric properties of the sample are investigated as a function of temperature over selected frequencies. The high dielectric constant and low dielectric loss of the material suggest that it can be used in advanced energy storage systems. The minimal activation energies in the high-temperature region determined from the slope of the linear fit of the temperature-dependent curve indicate the enhancement of electrical conductivity. Looking into the strong dependence of resistivity on temperature, the thermistor parameters are evaluated using the resistance at different temperatures, which suggests its possible application for a thermistor as well as a temperature sensor. The calculation of different thermistor parameters such as thermistor constant, sensitivity factor, and activation energy confirms a negative temperature coefficient of resistance behavior of the ferrites at different temperatures and frequencies.