Structural and magnetic properties of Mg-Zn ferrites (Mg1−xZnxFe2O4) prepared by sol-gel method

In this study, the Mg1−xZnxFe2O4 nanoparticles (x=0-0.9) were prepared by sol-gel method. These ferrites exhibit an inverse spinel structure and the lattice parameter increases as the substitution of Zn2+ ions is increased. At lower Zn content (0.1≤x≤0.5), saturation magnetization (Ms) increases, while it decreases at higher Zn content (x≥6). The remnant magnetization (0.17-2.0 emu/g) and coercive field (6.0-60 Oe) indicate a ferrimagnetic behavior. The average core diameter of selected ferrites is around 15 nm and the nanoparticles morphology is quasi spherical. The heating ability of some Mg0.9Zn0.1Fe2O4 and Mg0.7Zn0.3Fe2O4 aqueous suspensions indicates that the magnetic nanoparticles can increase the medium temperature up to 42 °C in a time less than 10 min