Influence of Ni substitution on structural, morphological, dielectric, magnetic and optical properties of Cu-Zn ferrite by double sintering sol-gel technique

Polycrystalline NiCuZn ferrite (NixCu0.3Zn0.7-xFe2O4; x = 0.2, 0.3, 0.4 and 0.5) were prepared through sol-gel auto combustion method applying double sintering technique. Structural, morphological, elemental analyses (EDS), Fourier-transform infrared spectroscopy (FTIR), Direct Current (DC) electrical resistivity, dielectric, magnetic and optical properties of prepared samples were analyzed. XRD profiles reveal the formation of simple cubic spinel structure without any traceable impurity. The average crystallite size lies within the range of 22-29 nm. Lattice parameter decreases with increasing Ni concentration. Room temperature DC resistivity was recorded from 6.39 x 10(5) to 3.79 x 10(5) Omega cm. Both dielectric constant ((epsilon)over dot) and loss factor (tan delta) were decreased with increase of frequency while AC conductivity increases. FTIR absorption peak occurred at three different frequency ranges at 570-577 cm(-1), 1635-1662 cm(-1) and 3439-3448 cm(-1). Magnetic properties were investigated by using vibrating sample magnetometer (VSM). Decreasing trends were observed for saturation magnetization (M-s), magnetic coercivity (H-c) and remanant magnetization (M-r) with the increase of Ni content. Optical band gap (similar to 2.70-2.79 eV) were calculated from diffuse reflectance data by using Kubelka-Munk function.