Magnetic properties of Li0.5Fe2.5O4 nanoparticles synthesized by solution combustion method

In this research, lithium ferrite (Li0.5Fe2.5O4) powders were prepared by solution combustion synthesis using glycine and citric acid fuels at various fuel to oxidant molar ratios (phi = 0.5, 1 and 1.5). Phase evolution, microstructure and magnetic properties were characterized by thermal analysis, infrared spectroscopy, X-ray diffraction, electron microscopy and vibration sample magnetometry techniques. Single-phase lithium ferrite was formed using glycine fuel at all fuel to oxidant ratios, while some impurity alpha-Fe2O3 phase was appeared using citric acid fuel at phi >= 1. The phase and crystallite size mainly depended on the combustion rate through fuel type. Bulky microstructure observed for citric acid fuel was attributed to its slow combustion, while the fast exhausting of gaseous products led to spongy microstructure for glycine fuel. The highest saturation magnetization of 59.3 emu/g and coercivity of 157 Oe were achieved for the as-combusted powders using glycine fuel.