Microwave sintering of nickel ferrite nanoparticles processed via sol-gel method

Magnetic nickel ferrite (NiFe₂O₄) was prepared by sol-gel process and calcined in the 2.45 GHz singlemode microwave furnace to synthesize nickel nanopowder. The sol-gel method was used for the processing of the NiFe₂O₄ powder because of its potential for making fine, pure and homogeneous powders. Sol-gel is a chemical method that has the possibility of synthesizing a reproducible material. Microwave energy is used for the calcining of this powder and the sintering of the NiFe₂O ₄ samples. Its use for calcination has the advantage of reducing the total processing time and the soak temperature. In addition to the above combination of sol-gel and microwave processing yields to nanoscale particles and a more uniform distribution of their sizes. X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and vibrating sample magnetometer were carried out to investigate structural, elemental, morphological and magnetic aspects of NiFe₂O₄. The results showed that the mean size and the saturation magnetization of the NiFe ₂O₄ nanoparticles are about 30 nm and 55.27 emu/g, respectively. This method could be used as an alternative to other chemical methods in order to obtain NiFe₂O₄ nanoparticles.