Optimization, Structural, Spectroscopic and Magnetic Studies on Stable Akaganeite Nanoparticles via Co-Precipitation Method

Abstract

With a view to achieve stable the ultrafine akaganeite (β-FeO(OH)) particles, they are synthesized by varying the molar concentration of dextrose, x = 0.2, 0.4, 0.6, 0.8, 1.0M, as chelating agent in co–precipitation method. The structural properties studied using the powder X–ray diffraction patterns show that an optimum concentration of dextrose for the formation of akaganeite is 0.6M. The particles possess tetragonal crystal structures and the size of grains is in the order of nanometer (~18 to 29nm). DSC curves explain the chemical reactions and phase transitions undergone by the sample. FT-IR spectra of the nanoparticles of akaganeite show the absorption bands at 491 and 445cm-1 in all the samples corresponding to the symmetric stretching vibrations of Fe-O bond and its ligands respectively in the octahedral co-ordinations. UV–Visible spectra of the present set of samples clearly exhibit a change in the optical bandgap from 1.97 to 2.14eV. The magnetic studies could bring out a weak ferrimagnetic behaviour accompanied by superparamagnetism in the akaganeite nanoparticles.