Effect of sintering temperature on electromagnetic properties of NiCuZn ferrite

Ni0.50Cu0.05Zn0.45Fe2O4 ferrite nanoparticles were processed through the sol–gel method using polyvinyl alcohol as a chelating agent. The dried powder after annealing (500 °C for 3 h) was compacted and sintered at three different temperatures (900, 950 and 1030 °C) for 1 h. In this article, optimum sintering temperature required for NiCuZn ferrite system, for obtaining good electromagnetic properties, suitable for Multilayer Chip Inductor (MLCIs) applications was studied. The structural, magnetic and dielectric properties were investigated as a function of sintering temperature. X-ray diffraction patterns for the sintered samples confirmed formation of single phase cubic spinel structure. Microstructure and grain size distribution for the samples were investigated by FESEM which displayed homogeneous grains of polyhedral shape by retaining almost temperature independent grain shape but with increased grain size along with the increase of sintering temperature. Saturation magnetization showed increasing trend with sintering temperature up to 950 °C and decreased after that. The sample sintered at 950 °C exhibited low magnetic losses, high saturation magnetization and high frequency stability of permeability with cut off frequency around 30 MHz.