Microemulsion-based method of synthesis of zinc-nickel ferrite and their magnetic properties

Solid solutions of nickel-zinc ferrites ZnxNi1-xFe2O4 were synthesized by two different methods: synthesis in microemulsions and by stepwise precipitation. The properties of the resulted nano-sized particles synthesized by two different methods were compared. It was found that the increase in zinc content leads to an increase in the lattice parameters. During the synthesis by the method of microemulsions, the temperature of a single-phase product formation is 400 °C, while by the method of precipitation, a single-phase product formation begins at 600 °C. It was shown that the materials synthesized by both methods have similar unit cell parameters. The average size of ferrite nanoparticles synthesized in microemulsions is smaller, lattice strain is higher compared to ferrites synthesized by stepwise precipitation. Also, lower treatment temperatures provide higher stoichiometry, and homogeneity of materials while magnetization difference is negligible. The particles of the obtained powders have high saturation magnetization Ms = 45.6 Am2/kg for synthesis from microemulsions and Ms = 44.8 Am2/kg for co-precipitated samples, the low coercive force Hc = 1.3 kA/m and Hc = 3 kA/m, respectively. Changes made make synthesized particles more applicable in film deposition, and manufacturing of high-quality magnetic coatings.