Electrochemical Synthesis for the Control of γ-Fe2O3 Nanoparticle Size. Morphology, Microstructure, and Magnetic Behavior

• Published in: Chemistry of materials 1999-01, Vol.11 (1), p.141-147
• Main Authors: Pascal, C, Pascal, J. L, Favier, F, Elidrissi Moubtassim, M. L, Payen, C
• Format: Article
• Language: English
• Subjects: Amorphous and nanocrystalline magnetic materials; quasicrystals; Amorphous and quasicrystalline magnetic materials; Clusters, nanoparticles, and nanocrystalline materials; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Domain effects, magnetization curves, and hysteresis; Exact sciences and technology; Magnetic properties and materials; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Magnetization curves, hysteresis, Barkhausen and related effects; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Mossbauer effect; other γ-ray spectroscopy; Mössbauer effect; other γ-ray spectroscopy; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Physics; Structure of solids and liquids; crystallography; Studies of specific magnetic materials
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm980742f

The electrochemical synthesis of nanoparticles of γ-Fe2O3 was performed in an organic medium. The size was directly controlled by the imposed current density, and the resulting particles were stabilized as a colloidal suspension by the use of cationic surfactants. The size distributions of the particles were narrow, with the average sizes varying from 3 to 8 nm. The amorphous character of the nanoparticles was clearly established by X-ray powder diffraction and TEM analysis. The microstructure of this phase could nevertheless be spectroscopically related to maghemite, γ-Fe2O3. 57Fe Mossbauer spectroscopy and magnetization measurements indicated that the dry powders exhibit superparamagnetic behavior at room temperature.