Study of magnetic properties and structural analysis of Ba-Ni-Zn ferrites prepared through a self-propagating high-temperature synthesis

BaxNiyZn1-x-yFe2O4 powders were synthesized at an oxygen pressure of 3 MPa using the reaction: Fe2O3+xBaO+yNiO+(1-x-y)ZnO+Fe→BaxNiyZn1-x-yFe2O4. The reaction mechanism is of the gas-solid type, and depends on the reduction and oxidation of iron (Fe) and various oxides such as NiO, ZnO, and BaO, respectively. A neutron diffraction analysis reveals that the final product is Ba0.45Ni0.02Zn0.43 Fe2O4 with lattice parameter a=0.84305 nm (χ2=2.89). The ferrites show soft magnetic properties in their hysteresis curves. The coercive force, the maximum magnetization, the residual magnetization and the susceptibility of Ba0.45Ni0.02Zn0.43 Fe2O4 amount to 6778 A/m, 21.16 Wb/m2 kg, 1.94 Wb/m2 kg and 0.028 m3/kg, respectively