Effect of Porous Structure on the Magnetic Properties of NixMgyZn1−x−yFe2O4 Magnetic Materials

We deal with the preparation of NiMgZnFeIII-SO4 layered double hydroxides (LDHs) with the layered precursor method and introduce excessive ZnO into the NiMgZnFeIII-SO4 LDHs to produce NixMgyZn1−x−yFe2O4 ferrites that contain massive ZnO. Then the NixMgyZn1−x−yFe2O4 ferrites are treated with NaOH solution to remove ZnO to produce the porous NixMgyZn1−x−yFe2O4 magnetic material: when y = 0, porous NiZnFe2O4 ferrite magnetic materials are obtained; when y ≠ 0, porous NiMgZnFe2O4 ferrite magnetic materials are obtained. From analyses of these two ferrites, their pore-forming mechanism and comparison of their properties before and after they undergo the alkali treatment, we find that after being treated by the NaOH solution, NiZnFe2O4/NiMgZnFe2O4 have better uniform-structure pores, which will greatly expand their pore volume, widen their application scope and improve their magnetic properties.