Comparative study of structural and magnetic properties of nano-crystalline Li0.5Fe2.5O4 prepared by various methods

Lithium ferrite has been considered as one of the highly strategic magnetic material. Nano-crystalline Li0.5Fe2.5O4 was prepared by four different techniques and characterized by X-ray diffraction, vibrating sample magnetometer (VSM), transmission electron microscope (TEM) and Fourier transform infrareds (FTIR). The effect of annealing temperature (700, 900 and 1050 deg. C) on microstructure has been correlated to the magnetic properties. From X-ray diffraction patterns, it is confirmed that the pure phase of lithium ferrite began to form at 900 deg. C annealing. The particle size of as-prepared lithium ferrite was observed around 40, 31, 22 and 93 nm prepared by flash combustion, sol-gel, citrate precursor and standard ceramic technique, respectively. Lithium ferrite prepared by citrate precursor method shows a maximum saturation magnetization 67.6 emu/g at 5 KOe.