Novel processing and magnetic properties of hematite/maghemite nano-particles

Hematite/maghemite nano-particles were synthesized by combustion method using different ratios of fuel. Effects of these ratios on crystalline phases, crystallite size, morphological and magnetic properties of the nano-particles have been investigated. The products were characterized by XRD, SEM and EDX techniques. Magnetic properties of the as prepared nano-particles were evaluated on a vibrating sample magnetometer. X-ray diffraction analysis indicates that low content of fuel promotes the formation of alpha ferric oxide, whereas high content of this fuel produces gamma ferric oxide with alpha ferric oxide. Varied morphology for the glycine-treated samples compared to untreated specimen was observed. The treatment with glycine brought about an increase in the concentration of ferric species at the as prepared solids as shown from EDX analysis. However, the mixture containing hematite/maghemite nano-particles led to better magnetic properties depending upon the presence of maghemite crystallites.