Magnetic Enhancement of γ-Fe2O3 Nanoparticles by Sonochemical Coating

• Published in: Chemistry of materials Vol. 14; no. 4; pp. 1778 - 1787
• Main Authors: Shafi, Kurikka V. P. M, Ulman, Abraham, Dyal, Ansil, Yan, Xingzhong, Yang, Nan-Loh, Estournès, Claude, Fournès, Léopold, Wattiaux, Alain, White, Henry, Rafailovich, Miriam
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.04.2002
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Fine-particle systems; Magnetic properties and materials; Physics; Small particles and nanoscale materials; Studies of specific magnetic materials; Hyperfine magnetic field; Moessbauer effect; Fourier transform spectroscopy; Magnetization; Magnetic ordering; Magnetic hysteresis; Organic silane; XRD; Infrared spectra; Experimental study; Deposition process; Nanoparticles; Vibrational modes; Coated particle; Acoustochemical reactions; Iron oxides
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm011535+

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.