Effect of Mg substitution on magnetic properties of Co1−xMgxFe2O4 nanoparticles investigated by EXAFS analysis

Co1−xMgxFe2O4 (x = 0.00, 0.25, 0.50, 0.75 and 1.00) nanoparticles were prepared by the hydrothermal method in Aloe vera extract solution. X-ray diffraction (XRD) results indicate a pure phase of all samples with the cubic spinel ferrite structure. TEM images reveal a decrease in average particle sizes from 37.03 ± 13.17 to 9.86 ± 2.63 nm with increasing Mg content. The X-ray absorption near edge structure (XANES) technique confirmed the existence of Co2+ and Fe2+, 3+ with partial substitutions of Mg cations in the structure. The magnetic properties of samples studied by vibrating sample magnetometer (VSM) indicated ferrimagnetism at room temperature. The saturation magnetizations (Ms) significantly decreased with increasing Mg content, relating to cation distribution revealed by the EXAFS results.