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

Abstract

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.

Magnetic, X-ray and Mössbauer studies on magnetite/maghemite core–shell nanostructures fabricated through an aqueous route

“…Interestingly, it has been observed that D TEM for T33 (8.2 nm) is smaller than D mag (9.86 nm) i.e., magnetic size is overestimated by approximately 10% in comparison to TEM size. Such overestimation was previously observed by few researchers and can be explained on the basis of either perturbation in the Langevin function caused by interparticle interactions that was ignored during tting 51 or the consideration of single size distribution of the particles. In order to get a better information, the magnetic sizes (D mag ) were also calculated by using eqn (7), 52,53 …”

Progress in the Preparation of Magnetite Nanoparticles through the Electrochemical Method

“…et al, 2002), (ii) hydrogen gas as a reducing agent of iron hydroxide (Franger S. et al, 2004;Manrique-Julio J. et al, 2016;Melnig V. and Ursu L., 2011), (iii) direct reaction between Fe 2+ and Fe 3+ (Karami H. and Chidar E., 2012;Ying T.Y. et al, 2002), and (iv) oxygen as oxidant agent and subsequent in-solution precipitation Gopi D. et al, 2016;Lozano I. et al, 2017;Pascal C. et al, 1999;Starowicz M. et al, 2011).…”

Synthesis of Nano‐γ‐Ferric Oxide by Thermolysis of the 2‐Mercapto‐5‐Methylpyridine‐N‐Oxide‐Iron(III) Complex via Factorial Design

“…c-Fe 2 O 3 (Maghemite) nanocrystallites is a red-brown material which has attracted great interest due to its variety of technological applications in modern industry [1][2][3][4][5][6]. It possesses various optical, electrical, and magnetic properties and has been used in color imaging, biochemical separations, information storage, gas sensors, catalysts, ferrofluids, pigments, etc.…”