Evaluation of structural, optical, and magnetic properties of Gd doped MnFe2O4 nanoparticles

In this study, the MnFe2O4 doped Gd (MnGdxFe2-xO4 with x = 0, 0.125, 0.25, and 0.5) magnetic nanoparticles were successfully synthesized and revealed the significant effect of Gd content on structural, optical, and magnetic properties. The replacement of Fe3+ ions by ion Gd3+ ions changed the crystallite size from 8.2 nm (x = 0) to 13.5 nm (x = 0.5). The band gap of Gd-doped MnFe2O4 increased with an increase of the x value. The magnetic curves showed that saturation magnetization (MS) and magnetic anisotropy (K) decreased simultaneously with the concentration of Gd3+ ions. The MS value reduced from 54.0 emu/g (MnFe2O4) to 35.4 emu/g (MnGd0.5Fe1.5O4). The K value dropped from 50.4 kJ/m3 (MnGd0.125Fe1.875O4) to 12.3 kJ/m3 (MnGd0.5Fe1.5O4). The substantial reliance of magnetic anisotropy on the doping concentration, namely this large change in K with a little change in size (8.2 nm–13.5 nm), demonstrated that doping is a suitable method for modifying the values of magnetic anisotropy of materials.