Fabrication and soft magnetic properties of ions substituted barium ferrite powder

Ni-Mg-Co substituted BaFe12O19 nano-powder was prepared by the sol-gel self-propagating combustion method,and the influence of different doping quantity and holding time on microstructure and magnetic properties was studied. The phase structure,microstructure and static magnetic properties were investigated by X-ray diffraction,transmission electron microscopy and vibrating sample magnetometer. It is found that holding time of heat treatment determines the magnetic properties of M-type barium ferrite before and after ion doping under 1 100 ℃ calcination temperature. The saturation magnetization of BaFe12O19 is only 137.9 A/m and coercivity is 41.8 kA/m after holding for 3 h,and saturation magnetization of BaNiMg0.9Co0.1Fe10O19is 143.3 A/m, the coercivity is 7.9 kA/m after holding for 3 h. This means that the magnetic properties of M type barium ferrite can be controlled in a wide range from the traditional permanent magnet to soft magnetic,so it can be widely used in the material space field.