Synthesis of nanocrystalline Mg0.6Cd0.4Fe2O4 ferrite by glycine-nitrate auto-combustion method and investigation of its microstructure and magnetic properties

Nanocrystalline Mg0.6Cd0.4Fe2O4 ferrite powders were produced by the glycine-nitrate auto-combustion method for the first time. The influence of the different molar ratios of glycine-to-nitrate G.N−1) on the characteristics of the prepared powders was systematically investigated by X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometry (VSM). Thermodynamic calculations revealed that the adiabatic flame temperature changes from 598.79 K to 1757.97 K by increasing the G.N−1 ratios from 0.30 to 0.85. The results confirmed that under fuel-lean combustion (G.N−1 = 0.30), Mg0.6Cd0.4Fe2O4 nanoparticles can be obtained at a significantly lower temperature and shorter synthesis time, compared to other preparation methods like standard ceramic and co-precipitation. The XRD and ICP results showed that the crystallite size of the powders changes in the range of 8-43 nm, and their Cd content notably decreases with increasing the G.N−1 values. The FE-SEM results proved that the porosity and size of the as-prepared ferrite nanoparticles drastically change with variations in the G.N−1 ratio. The evolution of phase, crystallite/particle size, and magnetic properties after annealing was discussed in detail. At the optimized annealing condition, the synthesized Mg0.6Cd0.4Fe2O4 ferrite offered a high saturation magnetization of 41.70 Am2 kg−1 and a coercivity of 1.92 kA m−1, indicating noticeably better soft magnetic properties compared to the same ferrite produced by the other wet chemical methods.