Study on the magnetic properties of low-fired NiCuZn ferrite prepared by a combined method

The NiCuZn ferrites were first prepared by the conventional mixed-oxide method with Fe₂O₃, NiO, ZnO and CuO analytical grade powders as starting materials. These materials were wet-mixed in a ball mill for relatively longer time to decrease the size of particles. After the mixed powders calcined, the sintering aids Bi₂O₃ were added (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 wt%) in the ferrite powders obtained. After the powders mixed by wet-milling and pressed into toroidal bodies, the green bodies were sintered at 900 °C and held for 3h in air then the sintered samples were tested and analyzed. The phase formation was evaluated with X-ray diffraction(XRD). The microstructures on the cross section of the samples were investigated using scanning electron microscopy(SEM). The initial permeability and Q-factor measurements were carried out on precision LCR meter(Agilent 4285) in the range of 0.1MHz-30MHz.