Structural and Magnetic Properties of Nanocrystalline Lithium–Zinc Ferrite Synthesized by Microwave-Induced Glycine–Nitrate Process

Abstract

In this study, nanocrystalline Li–Zn ferrites with the chemical composition Li0.5Zn x Fe2.5−x O4 (where x=0, 0.1,0.2,0.3,0.4,0.5) were synthesized by the glycine–nitrate process using glycine as a fuel, nitrate as an oxidizer and microwave oven as a heat source. The combustion reaction was studied by differential thermal analysis and thermogravimetry. The experimentally determined combustion reaction is extremely exothermic and it occurs at 170 ∘C. The as-synthesized powders were characterized by X-ray diffraction technique. X-ray diffraction data shows that nanocrystalline Li–Zn ferrite powders with a spinel structure have been formed successfully in all samples. Morphological studies using scanning electron microscopy and field emission scanning electron microscopy show agglomerated clusters with a lot of pores attributed to the large amount of gases released during the combustion synthesis with the particle size of 20–40 nm. The magnetic measurements on the as-synthesized powders and compacted samples were carried out using a vibrating sample magnetometer and an inductance/capacitance/resistance meter, respectively. Saturation magnetization increases with the increase in zinc concentration up to x=0.2 and then it decreases with the increase in the zinc content. In addition, maximum magnetic permeability also obtained for the sample with x=0.2 at different frequencies.