Abstract
Simple combustion route was implemented for the preparation of Mo-substituted magnesium ferrite nanoparticles; MgFe2-2xMoxO4 (x=0.0, 0.1, 0.2 and 0.3). Samples, with x=0.0, 0.1 and 0.2, revealed only the cubic spinel ferrite phase. Sample with x=0.3 showed very small amount of FeMoO4, beside MgFe2O4. The lattice parameter diminished with increasing molybdenum contents to x=0.1, then increased at x0.2. The saturation magnetization (M-s) increased from 15.65 to 32.05emu/g with low level of Mo6+ substitution (x=0.1), then declined with x>0.1. This is the first investigation to report M-s of Mg ferrite nanoparticles higher than its bulk value. The change in magnetic properties is correlated with cation distribution between tetrahedral sites (A) and octahedral sites (B). Mo6+ replaced the Fe3+ position in the tetrahedral A-sites for x=0.1. In samples with x0.2, Mo6+ occupied both A-sites and B-sites. Mo substitution decreased the crystallite size and increased the microstrain. Mo substitution in MgFe2O4 enhanced the photocatalytic action compared to bare MgFe2O4. The enhancement was due to the increase in structure defect that inhibits the electrons-holes recombination as well as the increase in surface area.