Effect of cobalt on structural, microstructural and magnetic properties of magnesium-zinc ferrite nanoparticles

Mg0.5-xCoxZnFe2O4 ferrite nanostructures with various amounts of Co2+ substitution (x= 0, 0.05, 0.10, 0.15) were prepared using a simple and inexpensive sol-gel method sol-gel route. Structural, microstructural and magnetic properties of the prepared powders were investigated by x-ray diffraction (XRD), Fourier transform infrared (FT-IR), field emission- scanning electron microscopy (FE-SEM), X-ray energy diffraction spectroscopy (EDAX) and vibrating sample magnetometer (VSM). The x-ray diffraction patterns showed that the prepared nanopowders have pure spinel structure without any other impurity phases. The average particle size of the powders was between 96-43 nm, using electron microscope images. Magneto-static analysis showed that the presence of cobalt ions has affected the saturation magnetization (Ms) and the coercivity (Hc). The Ms values decrease and then increase with increasing dopant (x). The lowest and highest values of Ms are related to x = 0.10 (16.5 emu/g) and 0.15 (39.6 emu/g), respectively. Based on this, the calculated Yafet-Kittel angle (Y-Kα) showed that the highest spin canting belongs to the sample with x = 0.10. Also, the value of Hc increases with x due to the high crystalline anisotropy of cobalt.