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 syn thesised from the iron sand using NaOH, HCl, and NaCl as a solvent. From the quantitative analysis of XRD spectra, the crystallite size (D), strain (ε), stress (σ), 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 (ε), and the energy loss function (Im(-1/ε)). 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.