Influence of solvothermal growth condition on morphological formation of hematite spheroid and pseudocubic micro structures and its magnetic coercivity

Influence of solvothermal growth condition on morphological formation and population of defects of hematite spheroid and pseudocubic micro structures and its magnetic properties were studied. Spheroid shaped crystals with different size were obtained from growth solution made of methanol, methanol-water, propanol and pseudocubic crystallites with dimension of 1.281 μm size were obtained with propanol-water solution combination at a growth temperature of 200 °C. UV absorption and magnetic properties of spheroid and pseudocubic micro structures were size and shape dependant. Spheroid shaped sample grown from precursor solution made of methanol gives intense UV absorption peaks at 360 nm and high coercivity (5.23 KOe) at room temperature. Reduction in magnetic coercivity and remanence of all samples at 5 K with respect to 300 K is attributed to antiferromagnetic nature of hematite with spheroid and pseudocubic morphology. High coercivity (6.2 KOe) at room temperature was observed from micro pseudocubic sample grown with propanol-water combination which is contributed to high aspect ratio, inter particle interaction and crystalline defects.