Structural and magnetic properties of Li-Al-substituted Ni-Zn-Cu ferrite powders prepared via chemical coprecipitation method

摘要

Li-Al substituted Ni-Zn-Cu ferrite powder specimens with the nominal composition Ni_(0.25-2x)Li_x Al_xCu_(0.15)Zn_(0.60)Fe_2O_4 (x = 0.00, 0.01, 0.02, 0.03, 0.04) were prepared via an improved chemical coprecipitation method. An X-ray diffractometer, a scanning electron microscope and a vibrating sample magnetometer were used to study their structural and magnetic properties. It is found that all the specimens exhibit typical single-phase spinel structures after annealing, and the saturation magnetization decreases with increase of x. The initial susceptibility first increases but then decreases, and obtains the maximum when x - 0.02, which shows the proper content of Li-Al substitutions is favourable for the increase of initial susceptibility. It is also found that the Li-Al substitutions affect the grain growth slightly.