Synthesis of NiFe2O4 nanocrystalline with various size by hydrothermal method

Pure NiFe2O4 nanocrystallines were synthesized by hydrothermal method under 0-7 mol/L alkali concentration and different surfactant. The structure and magnetism of powder were characterized by X-ray diffractometer, transmission electron microscope, Fourier transform infrared spectrometer and vibrating sample magnetometer. The crystal size of NiFe2O4 powder increases firstly and then decreases as alkali concentration increasing. Relatively, the circular NiFe2O4 crystallines become square crystallines. The samples have high saturation magnetization relative to the crystal size and low coercivity.