Polyol Approach for the Synthesis of Water Soluble Mn3O4 Nanoparticles Using PEG

Polyethylene glycol (Mwt 400 and 10,000) stabilized Mn3O4 nanoparticles were synthesized via the thermal decomposition approach. Structural characteristics were evaluated by XRD, FT-IR, TGA, VSM, and TEM analysis. Crystallite sizes were calculated as 10 +/- 3 and 15 +/- 5 nm for PEG-400 and PEG-10,000 stabilized Mn3O4 NPs, respectively. FT-IR and TGA proved the presence of PEG on the surface of Mn3O4 NPs. Magnetization measurements carried out at room and low temperatures revealed the superparamagnetic nature of the Mn3O4 NPs. The blocking temperature was detected as 39 K and thermomagnetic irreversibility starts at 40 K. Both coercive field and saturation magnetization increases as temperature decreases below T-C. Reduced magnetization compared to its bulk value has been explained by spin canting and presence of disordered spins. It was observed that the effects of different molecular weight PEG on the magnetic properties of the Mn3O4 nanoparticles are more or less the same.