The correlations between structural and optical properties of magnetite nanoparticles synthesised from natural iron sand

The correlations between structural and optical properties of magnetite (Fe3O4) nanoparticles were analyzed by using X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) Spectroscopy. The magnetite was synthesised from the iron sand using NaOH, HCl, and NaCl as a solvent. From the quantitative analysis of XRD spectra, the crystallite size (D), strain (epsilon), stress (sigma), energy deformation (u), porosity, and specific surface area were determined. The Kramers Kronig (K-K) relations was applied to the FTIR spectra to determine the optical properties: refractive index (n), extinction coefficient (k), the complex dielectric function (epsilon), and the energy loss function (Im(-1/epsilon)). The uniform strain was produced from the NaOH and HCl as the solvent. The magnetite had higher porosity with NaCl as a solvent and was directly proportional to the optical phonon vibration. We found a perfect correlation; when the difference between two optical phonon increases, the crystallite size decreases, and the strain will be uniform.