Study of the growth process of magnetic nanoparticles obtained via the non-aqueous sol-gel method

The growth process of iron oxide nanoparticles during synthesis via the non-aqueous sol-gel method has been analyzed. Samples obtained after reaching reaction temperature T (R) = 200 A degrees C and during the following 23 h of synthesis were characterized in detail by X-ray diffraction measurements, transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, Mossbauer spectroscopy, and magnetization measurements. The results show that the iron oxide nanocrystals are majorly composed of maghemite and grow in a faceted shape. The particle size increases gradually during the synthesis, and the structural and magnetic properties improve primarily during the first 6 h of reaction.