Synthesis, Characterization, and Magnetic Studies of - Nanoparticles

Very fine nano sized metal oxide, namely, iron oxide (α-Fe₂O₃) has been synthesized by precipitation method using ammonia as precipitating agent and characterized by using XRD (X-ray diffraction), TGA/DTA, surface area measurement, transmission electron microscopy (TEM), and magnetic measurements techniques. XRD studies show that iron oxide was formed as α-Fe₂O₃ instead of the commonly formed magnetite nanoparticles (Fe₃O₄) or a mixture of magnetite (Fe₃O₄) and maghemite (γ-Fe₂O₃, cubic), and it has rhombohedral structure. Magnetic measurements showed that iron oxide has five unpaired electrons and is ferromagnetic in nature, Ms value being 1.7 emu/g. The particle size of the synthesized iron oxide was determined by TEM. TEM images show that the size of particles of Fe₂O₃ varied from 15 nm to 49 nm with average crystallite size 35 nm.