Synthesis and characterization of nickel ferrite nanoparticles by chemical method

In this paper we synthesized nickel ferrite nanoparticles by using a chemical method. Synthesized nanoparticles were characterized by using X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Magnetic properties, size, purity, stoichiometry and morphology of the samples were determined. Some samples were calcined at different temperatures. We found that the size of nanoparticles increased with the increase in calcination temperature and the nanoparticles transformed from amorphous phase to crystalline phase. When the size of nanoparticles decreased to less than a critical size (10 nm) the nanomaterial underwent a transition from a ferromagnetic to a superparamagnetic.