Structural and magnetic properties correlated with cation distribution of Mo-substituted cobalt ferrite nanoparticles

Mo-substituted cobalt ferrite nanoparticles; CoFe2-2xMoxO4 (0.0 <= x <= 03) were prepared by a one-step solution combustion synthesis technique. The reactants were metal nitrates and glycine as a fuel. The samples were characterized using an X-ray diffraction (XRD), a transmission electron microscope (TEM) and a vibrating sample magnetometer (VSM). XRD analysis revealed a pure single phase of cubic spinel ferrites for all samples with x up to 0.3. The lattice parameter decreases with Mo6+ substitution linearly up to x=0.15, then nonlinearly for x >= 0.2. Rietvelcl analysis and saturation magnetization (M-s) revealed that Mo6+ replaced Fe3+ in the tetrahedral A-sites up to x=0.15, then it replaced Fe3+ in both A-sites and B-sites for x >= 0.2. The saturation magnetization (M-s) increases with increasing Mo6+ substitution up to x=0.15 then decreases. The crystallite size decreased while the microstrain increased with increasing Mo6+ substitution. Inserting Mo6+ produces large residents of defects and cation vacancies. (C) 2014 Elsevier B.V. All rights reserved,