Preparation and Magnetic Properties of MFe_2O_4 Nanoparticles by Modified Pechini Method

摘要

Nickel ferrite (NiFe_2O_4) nanoparticles have been synthesized by modified Pechini method in the presence of surfactant and certain amount of concentrated nitric acid. The obtained foamed gel precursors were characterized by thermogravimetry-differential thermal analysis (TG-DTA) to determine the thermal decomposition and subsequently calcined at different temperatures in the range of 500-800°C for 2h to obtain NiFe_2O_4 nanoparticles, which were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron micrograph (TEM), and vibrating sample magnetometer (VSM). The results showed that Ni ferrite nanoparticles obtained by modified Pechini method exhibited good dispersibility, uniform distribution, and good crystallinity, and the particle diameter of NiFe_2O_4 calcined at 500°C is almost 80 urn. Its saturation magnetization was 50.5 emu/g at the maximum magnetic field of 10 kOe at room temperature. The particle size, saturation magnetization, and coercivity of NiFe_2O_4 increased with the increase of the calcination temperature.