Effect of fuel content on structural and magnetic properties of solution combusted Mn0.8Zn0.2Fe2O4 powders

Single phase Mn0.8Zn0.2Fe2O4 powders were synthesized by solution combustion method. The solution combustion method relies on the exothermic self-sustained reactions in reactive solution containing of oxidizers and organic fuels. In this work, the effects of various amounts of glycine as fuel on the powder characteristics were investigated. The structure, cation distribution, microstructure, magnetic and microwave absorption properties were characterized by X-ray diffraction, electron microscopy and vibrating sample magnetometry techniques. The cation distributions determined by Bertaut method in which the observed reflection intensities compared with the calculated ones for supposed crystal structures. The Mn0.8Zn0.2Fe2O4 exhibited partially inverse structure in which Zn preferentially occupied tetrahedral (A) sites. The as-combusted Mn0.8Zn0.2Fe2O4 powders showed spongy structure due to the liberation a large amount of gaseous products. However, the porosity decrease with the increase of fuel content due to the increase of adiabatic combustion temperature. The saturation magnetization of the as-combusted Mn0.8Zn0.2Fe2O4 powders increased from 43 to 69 emu/g with the increase of  from 0.5 to 1 and then slightly decreases to 67 emu/g for =1.5. The highest saturation magnetization (69 emu/g) for =1 was attributed to the highest crystallite size and crystallinity. The coercivity also increased from 27 to 67 Oe with fuel content.