Synthesis and magnetic properties of Ni0.5MgxZn0.5-xFe2O4 (0.0 ≤ x ≤ 0.5) nanocrystalline spinel ferrites

In this work, structural and magnetic properties of Ni0.5Mg Zn0.5-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5) nanocrystalline ferrites synthesized via the co-precipitation method are reported. The ferrites are found to be at the nano-scale with sizes below 30 nm and seem porous in their general appearance. The structural properties were investigated using X-ray and Infrared (IR) spectra. X-ray Diffraction (XRD) patterns have been refined using the Rietveld method to find the lattice parameters. It was found that all these ferrites are a single-phase cubic spinel related structure belonging to the Fd-3m space group. Further, the positions, occupancy and Wyckoff s cationic position of the ions, in addition the lattice constant (a), the crystallite size (D) and the micro-strain of the composites have been analyzed and found to be affected by the variation of the Mg2+ ions concentration. The Vibrating Sample Magnetometer (VSM) technique showed that these nanoparticles are superparamagnetic with approximately impermanent magnetization of relatively high values. It was also found that the magnetization values of the Ni0.5MgxZn0.5-xFe2O4 (0.0 <= x <= 0.5) system increase with the existence of the Mg2+ and the Zn2+ contents together (at x = 0.1, 0.2, 0.3, 0.4) due to the increase in the super exchange interaction happening between the Fe3+ and the Ni2+ ions resulting from the occupation of the Mg2+ and the Zn2+ ions (nonmagnetic) to exclusively the A-sites as indicated by the Rietveld's structural analysis. These composites are expected to be promising for biomedical applications due to their superparamagnetic property below 30 nm.

Automated summary

This study reported the structural and magnetic properties of Ni0.5Mg Zn0.5-xFe2O4 nanocrystalline ferrites synthesized via the co-precipitation method. The ferrites exhibited superparamagnetic behavior and were found to be sensitive to the Mg2+ and Zn2+ contents.