Microstructure and magnetic properties of Ni0.75Zn0.25Fe2O4 ferrite prepared using an electric current-assisted sintering method

Using a Ni0.75Zn0.25Fe2O4 nanopowder synthesized by means of a hydrothermal method as a raw material, polycrystalline nickel zinc (NiZn) ferrite ceramics composed of sub-micron grains were successfully prepared via an electric current-assisted sintering method. Temperatures ranging from 800 degrees C to 950 degrees C and a dwell time of 20 min were employed. The phase composition and microstructure of the samples were characterized via X-ray diffraction and scanning electron microscopy, respectively. Moreover, the magnetic properties of the samples were investigated using a vibrating sample magnetometer and a ferromagnetic resonance system. The results revealed that each sintered sample was mainly composed of a spinel phase. With increasing sintering temperature, the specific saturation magnetization increased from 71.85 emu/g to 74.58 emu/g, owing mainly to the increase in the relative density and the average grain size of the NiZn ferrites. The coercivity and ferromagnetic resonance linewidth of the ferrite ceramics decreased monotonically with increasing sintering temperature, owing mainly to the magnetostriction coefficient, saturation magnetization, and porosity of the sintered ferrites.

Automated summary

Polycrystalline nickel zinc (NiZn) ferrite ceramics composed of sub-micron grains were successfully prepared via an electric current-assisted sintering method using a Ni0.75Zn0.25Fe2O4 nanopowder. The specific saturation magnetization of the sintered samples increased with sintering temperature, while the coercivity and ferromagnetic resonance linewidth decreased.