Investigation effect of Non-thermal coating Silica on the structural and magnetic properties of Fe3O4 nanoparticles

In this study، Fe3O4/SiO2 core-shell magnetic nanoparticles (NPs) by two-step process were synthesized. First، Fe3O4 NPs by co-precipitation method of iron ions (Fe3+ and Fe2+) in an alkaline medium without using surfactant were synthesized and then silica shell with a non-thermal method without the use of linkers were installed on Fe3O4 NPs. facility of this method is noticeable. Results of X-ray powder diffraction patterns show that the inverse spinel structure of Fe3O4 and amorphous silicon was made. Fourier transform infrared spectroscopy confirmed the formation of these structures. There is no additional peak in XRD pattern which indicates that the prepared particles have pure Fe3O4 phase. TEM images show that core-shell structure is formed and mean size of NPs is 20 nm. VSM analysis showed that saturation magnetization of Fe3O4 nanoparticles after coating with silicon decreased.