Preparation of MnFe2O4 Nanoparticles Via a Facile Water-Glycol Solvothermal Approach

A novel solvothermal method is demonstrated to synthesize paramagnetic MnFe2O4 nanoparticles with narrow size range around 25 nm. Fe2+ is used as iron source without adscititious oxidant, and the synthesis process is performed in water-glycol solvent. Some factors, including the reaction time, temperature, and surfactants, are investigated. The samples are characterized by XRD, SEM, TEM, and VSM. The experimental results indicate that ethylene glycol is a critical factor for controlling size and magnetic properties, and MnFe2O4 nanoparticles belong to paramagnetic material and their coercivity reduces from 54 to 22 Oe with the treatment time changed from 6 to 24 h at 160°C.