Gd³⁺ substituted of [Mn_0.5Zn_0.5Gd _xFe_2-xO₄ (x= 0.1, 0.2, 0.3, 0.4) ferrites for ferrofluids application

Gd³⁺ substituted MnZn ferrites [Mn_0.5Zn _0.5Gd_xFe_2-xO₄ (x = 0.1, 0.2, 0.3, 0.4)] nanoparticles have been explored for ferrofluid applications. The oleic acid coated water base ferrofluids of these ferrites are prepared by chemical co-precipitation. The effect of Gd³⁺ ions on structural morphological and magnetic properties of these samples are characterized by X-ray diffraction, FTIR, EPR and dc magnetization techniques. The crystallite size, particle size and saturation magnetization increases with the increase of Gd³⁺ ions concentration while lattice parameter and lattice strain reduces. The g-value, peak-to-peak linewidth and spin concentration evaluated from EPR spectra correlated with cations occupancy.