Effect of addition on the structure and magnetic properties of Ni_1–xA_xFe₂O₄ prepared via sol-gel method

The Ni_1–xA_x Fe₂O₄ (A=Co, Mg; x=0, 0.5) spinal ferrite were compact in chemical "sol-gel" process. The structure and magnetic properties of the samples were done by XRD and VSM. The heat treatment for the samples was performed at 700°C for 2 hours. The crystalline size of NiFe₂O₄, Ni_0.5Co_0.5 Fe₂O₄ and Ni_0.5Mg_0.5 Fe₂O₄ were 34.7 nm, 26.8 nm and 29.8 nm, respectively and magnetic measurements showed that the saturation magnetization of these materials were 48.1 emu/g, 34.4 emu/g and 20.36 emu/g, respectively. The values of coercivity (H_c) of the NiFe₂O₄, Ni_0.5Mg_0.5 Fe₂O₄ and Ni_0.5Mg_0.5 Fe₂O₄ are 182 Oe, 460 Oe and 85Oe.