Effect of Citrate on the Size and the Magnetic Properties of Primary Fe3O4 Nanoparticles and Their Aggregates

The size, size distribution and magnetic properties of magnetite nanoparticles (NPs) prepared by co-precipitation without citrate, in the presence citrate adsorbed post-synthesis were studied X-ray Diffraction (XRD), Dynamic Light Scattering (DLS), Electron Paramagnetic Resonance (EPR) magnetization measurements. aim this investigation was to clarify effect ions on NPs. primary NPs, as determined analysing width diffraction peaks using various methods, ca. 10 nm for bare NPs with post-synthesis, whereas it around 5 co-precipitated citrate. DLS measurements show that three types form aggregates (100–200 diameter) but dispersions citrate-coated are more stable against sedimentation than those sizes distributions XRD good agreement domains obtained fitting vs. field intensity curves. Magnetization curves kinds sample superparamagnetic.