Superparamagnetic iron oxide nanoparticles: effect of iron oleate precursors obtained with a simple way

The objective of the study was to investigate the effect of different amounts of iron oleate precursor with different oleic acid amounts on the properties of the synthesised nanoparticles by thermal decomposition. The iron oleate precursors which formed from oleic acids in the order of 0.5, 1.0, 1.5 and 2.0 g, and 0.1 g iron powder was prepared under 200 °C seperately, using a facile solvothermal method under study. Thermal analysis of iron oleat precursors by a thermogravimetric analysis (TGA) revealed that the different amount of oleic acid was seen to have an impact on the thermal properties of iron oleat complexes. During the synthesis of nanoparticles, iron oleate complex in 1-hexadecane kept refluxing for 3 h under air atmosphere resulting in the formation of nanoparticles. The fourier transform infrared spectra measurements and the TGA analysis disclosed that nanoparticles were coated with oleic acid. To the X-ray diffraction patterns, all samples are iron oxide nanocrystals and their crystal sizes increased from 6.4 to 9.8 nm with decreasing oleic acid. Also, the sizes of nanoparticles were found to be in same range as confirmed with the surface observation by a transmission electron microscope. The magnetic properties obtained from a vibrating sample magnetometer revealed that all nanoparticles are superparamagnetic at room temperature. Also, their saturation magnetizations were up to 33.2 emu/g. It is seen that the nanoparticles are superparamagnetic with the desired structural and corresponding magnetic properties and therefore, they could be thought to be convenient for biomedical applications as the particles can be transferred to aqueous phase.