چكيده به لاتين
Nowadays, the synthesis of spinel ferrite nanoparticles with high crystallinity and good control on shape, size, and size distribution, and as a result, optimum magnetic properties that are used in medical applications such as magnetic hyperthermia, is one of the interesting subjects in researches. The lack of toxicity and decreasing the consumption concentration of nanoparticles could effectively affect the application rate of these materials for in-vitro applications. Different parameters in thermal decomposition methods controlling the magnetic properties were studied such as the ratio of precursors to surfactants, reflux temperature, and holding time in reflux temperature to optimize magnetic and heating properties. For the investigation of structural and magnetic properties the X-ray diffraction pattern (XRD), Fourier Transformation Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM) and Magnetometer vibration sample (VSM) was done. Pure Nickel ferrite nanoparticles were synthesized in the absence of a solvent with the ratio of precursors: surfactants as 1:9 at 330˚C and 60 minutes. The saturation magnetization and coercivity were respectively 34.4 emu/g and 58.7 Oe. The highest saturation magnetization was obtained in Nickel ferrite with an equal ratio of precursors to surfactants. In these nanoparticles, the saturation magnetization and coercivity were 49.2 emu/g and 21.6 Oe respectively. To improve biocompatibility and heating characteristics of nickel ferrite nanoparticles, magnetite as a biocompatible spinel ferrite was coated on nickel ferrite nanoparticles with a seed-mediated method. This process increased the magnetization of nanocomposite in comparison with nickel ferrite nanoparticles. The variation of reflux temperature in absence of solvent as we considered didn’t have a considerable effect on the particle size of nickel ferrite nanoparticles.
