EFFECT OF COPPER OXIDE ON THE GRAIN GROWTH AND INITIAL PERMEABILITY OF Mg–Cu–Zn FERRITES

摘要

The microstructure and magnetic properties of Mg–Cu–Zn ferrites prepared by using solid-state reaction method have been investigated. X-ray diffraction (XRD), a scanning electron microscope (SEM), impedance analyzer and a vibrating sample magnetome- ter (VSM) were utilized in order to study the effect of copper substitution and its impact on the crystal structure, grain size, microstr cture and magnetic properties of the Mg–Cu–Zn ferrite. The formation of cubic spinel phase was identified using XRD technique. The microstructures of the samples show that the grain growth is greatly enhanced by the addition of CuO which is attributed to the liquid phase during sin- tering. The average grain size (Dm) increases significantly with increasing Cu content. The initial permeability (μ0) of the samples increases appreciably with increasing Cu content which is attributed to the increase of grain size and density of the samples. The resonance frequency (fr) of the samples shifts toward the lower frequency as the Cu content increases. The sharp fall of μ0 in μ0 T curves is observed for all the samples which indicate the homogeneity of the samples. The saturation magnetization (Ms) of the Mg–Cu–Zn ferrites increases slightly with increasing Cu concentration.