Low‐Temperature Synthesis of NiFe2O4by a Hydrothermal Method

Nickel ferrite (NiFe 2 O 4 ) nanoparticles were successfully synthesized via a hydrothermal process and characterized by X‐ray diffraction and transmission electron microscope techniques. The effects of reaction temperature, holding time, and RH ratio (isopropyl alcohol/water) were discussed. The NiFe 2 O 4 nanoparticles could be obtained at 60°C within 3 h. The crystallization of the spinel ferrites was promoted by the increase in reaction temperature, holding time, and RH ratio.