The synthesis of Co1−xDyxFe2O4 nanoparticles and thin films as well as investigating their magnetic and magneto-optical properties

• Co1−xDyxFe2O4 particles were obtained by co-precipitation.
• Doping of Dy3+ ions could effectively alter the inversion degree of the spinel.
• The ferrite coercivity was enhanced by 150% after adding Dy.
• The perceptible shifts of peak rotations were observed in the Kerr spectra.

The modification and optimization of the magnetic and magneto-optical properties of cobalt ferrite are of great importance due to their various applications in well-known scientific and industrial categories. In order to observe the effect of adding Dy3+ to the cobalt ferrite composition, Co1−xDyxFe2O4 (0≤x≤0.1) ceramic nanoparticles were synthesized by the co-precipitation chemical method and then their microstructure and magnetism were investigated through x-ray diffractometry, TEM micrography, IR spectroscopy and VSM magnetometry. The polar magneto-optical Kerr effect of the thin film specimens was also studied. The results reveal that the doping of Dy3+ ions could effectively alter the inversion degree of the spinel structure and the following magnetic and magneto-optical features. The ferrite coercivity was enhanced by 150% after adding Dy. The perceptible shifts of peak rotations were observed in the Kerr spectra for the Dy-doped CoFe2O4 films. Furthermore, TC had a descending trend with the addition of Dy from 440 °C to 420 °C for Co0.95Dy0.05Fe2O4.