Temperature dependent electrical properties of co-precipitated magnesium doped lithium nanoferrites

Abstract

Due to a number of unique properties, nanoferrites are considered among the most emerging materials for the manufacturing of microwave devices. In past few years, different elemental compositions of nanoferrites were fabricated for this purpose. In our work, magnesium-doped lithium ferrites (Li2−xMgxFe2O4.5−δ, where x = 0.0 to 1.0) were synthesized by using co-precipitation method in optimized conditions. Structural analysis was done by using X-ray diffraction (XRD); this data was further used to calculate the porosity, phase purity and crystallite size. The XRD results confirmed the formation of spinel structure for all the samples. The surface morphology of the prepared samples was examined by using scanning electron microscope that showed particle like morphology. Thermogravimetric analysis and differential scanning calorimetry were used to investigate the phase transition and melting point of the prepared samples respectively. The analysis showed the phase transitions at two temperature ranges and the melting point of the all the samples was above 900 °C except for composition x = 0.4. Dielectric loss, dielectric constant, AC electrical conductivity and DC electrical resistivity were studied as a function of temperature. Curie temperature was also estimated from the temperature dependent conductivity data and that were observed to be decreased with increase in Mg concentration. The result obtained from the electrical analysis of the prepared samples confirmed that they could be used in frequency dependent devices.