Preparation and magnetic properties of Ni0.25Cu0.25Zn0.5 ferrite from microwave-induced combustion

Abstract

Ni–Cu–Zn ferrite powders were successfully synthesized by microwave-induced combustion process. The process took only 15min to obtain as-received Ni–Cu–Zn ferrite powders. The resultant powders annealed at different temperature and were investigated by differential thermal analysis/thermogravimetry, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and vibrating-sample magnetometer. The as-received powders showed the formation of cubic ferrite with a saturation magnetization (Ms) of 63emu/g. The Ms increased to 75emu/g for the sample annealed at 700°C for 2h and the intrinsic coercive force (Hc) reached at 290Oe. The toroidal specimen sintered at 950°C for 4h presents the optimum initial permeability of 528 and the maximum quality factor of 62. The high initial permeability and large quality factor were closely associated with a higher densification.