The Synthesis of Maghemite and Hematite (γ-Fe2O3, α-Fe2O3) Nanospheres
Maghemite and hematite nanospheres were synthesized by using the Sol-gel technique. The structural properties of these nanosphere powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM),and pore size distribution.Hematite phase shows crystalline structures.The mean particle size that resulted from BET and XRD analyses were 4.9 nm and 2 nm. The field emission scanning electron microscopy shows iron-oxide powder is composed of nanosized particles, but in nanosized aggregates (agglomeration of particles). It can be seen from transmission electron microscopy that the size of the particles are very small which is in good agreement with the FESEM and the Xray diffraction. TEM and FESEM confirmed that the iron-oxide powder is composed of sizes from 8 nm to 10 nm. The BET and pore size method were employed for specific surface area determination.
Duk Yong Yoon, Suk-Joong L. Kang, Kwang Yong Eun and Yong-Seog Kim
M.A. Dar et al., "The Synthesis of Maghemite and Hematite (γ-Fe2O3, α-Fe2O3) Nanospheres", Materials Science Forum, Vols. 534-536, pp. 157-160, 2007