Influence of zinc substitution on magnetic and electrical properties of MgCuZn ferrite nanocrystalline powders prepared by sol-gel, auto-combustion method

The ferrite compositions Mg0.80-xCu0.20ZnxFe2O4 with x=0.5, 0.55, 0.60 and 0.63, were synthesized through nitrate-citrate gels auto-combustion method. The autocatalytic nature of the combustion process has been studied by thermal analysis (DTA and TG) of the dried gels. The as-burnt powders were calcined at 800 degrees C for I h and then pressed ferrite parts were sintered at 900 degrees C for 4 h. The as-burnt powders and calcined powders were characterized with respect to phase identification, grain size and lattice parameter determination using X-ray diffraction. The sintered ferrites have been investigated for their electrical and magnetic properties such as saturation magnetization, initial permeability. AC-resistivity, dielectric constant. dielectric loss tangent as a function of zinc content. The initial permeability, saturation magnetization, dielectric constant and dielectric loss were found to increase and AC-resistivity was decreased with Zn substitution for Mg. The powder prepared is suitable for the application in multilayer chip inductor due to its low-temperature sinterability, good magnetic properties and low loss at high frequency. (C) 2008 Elsevier B.V. All rights reserved.