Influence of different surfactants on morphological, structural, optical, and magnetic properties of α-Fe2O3 nanoparticles synthesized via co-precipitation method

α-Fe2O3 nanoparticles were synthesized using ferric chloride (FeCl3·9H2O), ferrous chloride (FeCl2·6H2O), and sodium hydroxide (NaOH) via simple co-precipitation method in the absence and presence of four separate and commonly used surfactants such as cetyltrimethylammonium bromide (CTAB,) polyvinylpyrrolidone K25, polyvinyl alcohol, and ethylenediaminetetraacetic acid. The aim of this study is to see whether different surfactants have an effect on the morphological, structural, optical, and magnetic properties of iron oxide nanoparticles. The X-ray diffraction data confirmed rhombohedral crystallographic structure for α-Fe2O3 sample. The average crystallite size for synthesized nanoparticles using the co-precipitation method with (and without) surfactant was calculated to be ∼ 15 ± 4.7 nm to 20 ± 1.2 nm. The transmission electron microscopy studies revealed spherical and some rod-like morphology of nanoparticles prepared with (and without) surfactant. Surfactant-assisted α-Fe2O3 nanoparticles showed a blue shift in optical absorption spectra due to the quantum confinement effect. The functional properties of nanoparticles are unaffected by the surfactant. At room temperature, all samples had a magnetization curve that was typical of ferromagnetic behavior, with the exception of α-Fe2O3 nanoparticles prepared with CTAB surfactant, which had almost superparamagnetic behavior.