Structural and magnetic properties of Mg substituted NiCuZn Nano Ferrites

The present paper examines the effect of magnesium substitution on structural and magnetic properties of NiCuZn nano ferrites synthesised by sol-gel method. The prepared samples were characterised by using X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FE-SEM) and Vibration sample magnetometer (VSM) techniques. The phase identification, unit cell parameter and crystallite size was determined using XRD analysis. The lattice constant reduced with increasing Mg content. Room temperature saturation magnetisation and coercivity showed reverse trend with increasing Mg content. Curie temperature (T_c) obtained from the thermo magnetic curves increases with Mg concentration. The initial permeability (μ_i) decreased with increasing Mg content. This is due to reduced magnetisation, grain size and increased magneto-crystalline anisotropy constant. Simultaneously, there is an upward shift of domain wall relaxation frequency with increasing Mg content. Also the permeability is observed to be constant up to 30 MHz frequency range showing compositional stability and quality of the material. The prepared samples were suitable for applications in Multilayer Chip Inductors due to their invariable permeability up to 30 MHz frequency and high thermal stability along with low sintering temperature.