The effect of magnetic field on the magnetic property of Agar/Fe3O4 nanocomposite

Agar/Fe3O4nanocomposites were synthesized in the presence of an external magnetic field (~ 0.4 Tesla) and their characteristics were compared to the samples synthesized without considering the external magnetic field. In this study, we used Fe^2+ and Fe^3+ for synthesizing Fe3O4 magnetic nanoparticles in the presence of agar as a polymeric additive, by co-precipitation technique. Vibrating sample magnetometer (VSM) analysis of the samples revealed the saturation magnetism as 33.92 emu/g and 38.92 emu/g for the synthesized samples in the absence and presence of external magnetic field, respectively. The results of scanning electron microscopy (SEM) images showed that the aggregation of magnetic nanoparticles is related to the magnetic property. Magnetic dipole alignment was increased by the sample synthesized in the external magnetic field. The Fourier transforms infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) pattern were also applied to characterize the magnetic nanocomposites.