Synthesis and characterization of iron oxide nanoparticles prepared hydrothermally at different reaction temperatures and pH

Abstract

Iron oxide nanoparticles were synthesized with Fe+2 and Fe+3 precursors in a 1 : 2 ratio by using the hydrothermal method under different reaction temperatures and alkaline conditions. The iron oxide nanoparticles were characterized for structure, morphology, optical and magnetic properties. X-ray diffraction analysis confirmed that the samples prepared at different hydrothermal temperatures exhibited a magnetite structure, the increased intensity of the peaks indicates a high degree of crystallinity. The transformation of goethite to Fe3O4 structure was observed with variation of the pH value. The morphological study revealed that some samples exhibited spherical particles and some others exhibited a mixed morphology of spheres and rods. The iron oxide synthesized at 190 °C exhibited better magnetic properties due to the uniform distribution of spheres with particles size in the range, 18 – 25 nm.