The effect of surface modification on the morphology and magnetic properties of NiFe2O4 nanoparticles

Three NiFe2O4/SiO2 nanocomposites have been obtained by dropping different silica source into ferrite sol in this study. X-ray fluorescence spectroscopy and X-ray diffractometer are, respectively, used to detect the content of nickel ferrite and crystalline phase in the formed nanocomposites. Transmission electron microscopy characterization shows a more-ordered array of NiFe2O4 nanoparticles in silica matrix after the particles are modified by a coupling agent, APS, before TEOS and sodium silicate. Magnetic measurements indicate that the lower dipole–dipole interactions between NiFe2O4 nanoparticles have been obtained after surface modification.