Study on Crystallization and Magnetic Property Deviation of Ni-Zn-Cu Ferrite Depending on the State of the Starting Material in the Annealing Process

Abstract

The spinel structure of the nanosize powder (Ni0.3Zn0.3Cu0.4Fe2O4) substituted by Ni, Zn, and Cu was fabricated by the sol-gel process. Changes in weight, crystal formation, and magnetic properties were observed by XRD, TG-DTA, VSM in the annealing process of the sol and gel. The saturation magnetization of the sol showed 54.8–58.6 emu/g at 500–800°C, and the gel showed 52.3–56.8 emu/g at 600–800°C. The coercive force of the sol decreased in the range −136 Oe to −11.4 Oe at 500–800°C, and the gel decreased in the range −95 Oe to −44 Oe at 600–800°C. Therefore, the deviation of the annealing temperature of the nanopowder fabricated in the sol process and the gel process was about 100°C.