Optimization of sintering on the structural, electrical and dielectric properties of SnO2 coated CuFe2O4 nanoparticles

An ever first attempt to synthesize nanocomposites of SnO2 coated CuFe2O4 has been made using urea–nitrate combustion method. Effect of various concentrations of SnO2 (1, 5, 10 and 20 wt.%) at three different sintering temperatures viz., 800, 1000 and 1100 °C for optimizing the compound formation has been studied individually. The synthesized materials were characterized by XRD, TEM, HRTEM, SAED, SEM, FT-IR, UV–vis, electrical conductivity and impedance spectra measurements. The XRD spectra reveal that 1100 °C-sintered sample is of ultra pure and well-defined crystalline nature irrespective of the concentration of SnO2. The grain size of the materials has been found to get increased as a function of sintering temperature and the extent of SnO2 substitution. The TEM and HRTEM figures evidence the nanocrystalline nature of the product. SAED pattern confirms the presence of single phase and polycrystalline of the final product. The band gap values were calculated from UV–vis spectra, which confirm the lowest band gap value for the 5 wt.% SnO2 added sample. The solid-state impedance and the electrical properties of the materials are in favour of the grain and grain boundary effect and the normal behavior of spinel compounds, respectively.