Magnetic enhancement of g-Fe2O3 nanoparticles by sonochemical coating

Kurikka V. P. M. Shafi (1) , Abraham Ulman (1) , Ansil Dyal (1) , Xingzhong Yan (2) , Nan-Loh Yang (2) , Claude Estournès (3) , Léopold Fournès (4) , Alain Wattiaux (4) , Henry White (5) , Miriam Rafailovich (5)

1 Department of Chemical Engineering and Chemistry
2 University at Albany - Department of Chemistry
3 IPCMS - Institut de Physique et Chimie des Matériaux de Strasbourg
4 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
5 Department of Materials Sciences and Engineering

We show that sonochemistry is an efficient and facile route for quantitative coating of γ-Fe2O3 nanoparticles with octadecyltrihydrosilane (OTHS, CH3(CH2)17SiH3). The presence of C−H stretching (2950−2850 cm-1) and bending (1475−1375 cm-1) bands, and the absence of peaks at 2150 and 925 cm-1 (Si−H stretching and bending respectively) confirm the presence of grafted hydrocarbon chains in the irradiated sample, hence the reaction of OTHS with γ-Fe2O3 nanoparticles. The coated nanoparticles show increased magnetization compared to the uncoated ones. X-ray diffraction, magnetization studies, Mössbauer spectra, and electron paramagnetic resonance spectra reveal that the magnetic ordering is more prominent in the OTHS-coated γ-Fe2O3 sample because of improved crystallinity.

Mots clés: Magnetism; Nanoparticles; Sonochemistry; Coating; Iron oxide

Domaines: Matériaux

Kurikka V. P. M. Shafi, Abraham Ulman, Ansil Dyal, Xingzhong Yan, Nan-Loh Yang, et al.. Magnetic enhancement of g-Fe2O3 nanoparticles by sonochemical coating. Chemistry of Materials, 2002, 14 (4), pp.1778-1787. ⟨10.1021/cm011535+⟩. ⟨hal-00713091⟩