Synthesis, characterization and magnetic properties of γ-Fe2O3 nanoparticles via a non-aqueous medium

Acicular shaped gamma-Fe2O3 nanoparticles (major axis: 17 +/- 1 nm; minor axis: 1.7 +/- 1 nm) have been prepared using lauric acid as a non-aqueous medium. The products were investigated by IR, TG-DTA, XRD, Raman, SEM, TEM and magnetization measurements. For the preparation Of pure gamma-Fe2O3 nanoparticles, the suitable condition of the molar ratio of lauric acid to iron nitrate is set 2:1 and the appropriate temperature lies in the range 573-673 K. Besides, either pure alpha-Fe2O3 or a mixture of gamma-Fe2O3 and alpha-Fe2O3 can also be obtained with the change of the molar ratio of lauric acid to iron nitrate. The experimental results indicate that the particle sizes, thermal stability and magnetic properties of the iron oxide strongly depend on the conditions in the preparation. (C) 2003 Elsevier Inc. All rights reserved.