nonlinear optical, magnetic, and Mössbauer spectral properties of some iron(III) doped silica xerogels

• Published in: Journal of materials science Vol. 41; no. 10; pp. 2839 - 2849
• Main Authors: Rebbouh, L, Rosso, V, Renotte, Y, Lion, Y, Grandjean, F, Heinrichs, B, Pirard, J.-P, Delwiche, J, Hubin-Franskin, M.-J, Long, Gary J
• Format: Journal Article Web Resource
• Language: English
• Published: Heidelberg Kluwer Academic Publishers 01.05.2006; Springer; Springer Nature B.V; Springer Science & Business Media B.V
• Subjects: AEROGELS; CATALYSTS; Chemistry; Chimie; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Curie temperature; Dependence; drying; emus; energy; Engineering, computing & technology; Exact sciences and technology; Gels; General and physical chemistry; Ingénierie, informatique & technologie; Iron; Irradiance; light intensity; Magnetic anisotropy; Magnetic permeability; Magnetic properties; Materials science; Materials science & engineering; NANOPARTICLES; Nonlinear optics; Optical properties; PARTICLES; pellets; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physical, chemical, mathematical & earth Sciences; Physics; Physique; Physique, chimie, mathématiques & sciences de la terre; refractive index; Refractivity; Science des matériaux & ingénierie; silica; Silicon dioxide; SOL-GEL; Sol-gel processes; sol-gel processing; Spectra; spectral analysis; SYSTEMS; temperature; Tetraethyl orthosilicate; Xerogels; Magnetization; Nanoparticle; Spectral properties; Paramagnetism; Moessbauer spectrometry; Experimental study; Silica; Solid; Magnetic susceptibility; Particle; Iron III; Energy; Sol gel process; Magnetic anisotropy; Optical properties; Defect; Xerogel; Magnetic properties; Drying
• ISSN: 0022-2461; 1573-4803; 1573-4803
• DOI: 10.1007/s10853-006-6336-3

Iron(III) species dispersed in silica have been synthesized with a sol-gel process. The iron(III) was introduced as the acetylacetonate complex into a solution of tetraethoxysilane to yield, after evaporative drying, pellets or monoliths. Two gels were dried very slowly over a period of five months in order to prepare a defect free monolith useful for nonlinear optical studies. Z-scan experimental studies on the resulting, transparent, monolithic, doped solid revealed an optical Kerr effect, a third order nonlinear optical phenomenon showing a linear dependence of the refractive index on the irradiance with a nonlinear refractive index, n₂, of −1.95 × 10⁻¹¹ cm²/W. Magnetic susceptibility studies between 4.2 and 295 K revealed paramagnetic behavior with a Curie constant of 4.433 (emu/mol)K and a Weiss temperature of −7.1 K. Magnetization studies at 5 K and at applied fields of up to 4 T and Mössbauer spectral studies between 4.2 and 295 K revealed a 50:50 mixture of paramagnetic species and nanoparticles with an average particle radius of 1.3 ± 0.2 nm. A blocking temperature of 70 K and a magnetic anisotropy energy of 2.4 × 10⁵ J/m³ are derived from the Mössbauer spectra.