Magnetically textured γ-Fe2O3 nanoparticles in a silica gel matrix: Optical and magneto-optical properties

Abstract

Optical and magneto-optical properties of maghemite superparamagnetic particles dispersed (f=0.28 vol % γ-Fe2O3) in a silica gel matrix have been studied at room temperature in the 1.5–3.7 eV spectral range. A permanent optical anisotropy can be induced when applying a magnetic field during the sol-gel freezing process. The permanent linear dichroism and birefringence in such in-plane magnetically textured samples are attentively studied. The spectral dispersion of Faraday effects in our textured samples is analyzed taking into account the in-plane optical anisotropy. Such a composite material is a promising candidate for future magneto-optical applications.

Synthesis and magneto-electrical properties of MFe2O4 (Co, Zn) nanoparticles by oleylamine route

“…Magnetic nanoparticles (MNPs) which have been the most investigated materials are current research due to the their potential applications in a wide range of fields such as magnetic resonance imaging [1], magneto-optical devices [2][3][4], biomedical drug delivery [5,6] and gene delivery [7] and catalysts [8,9]. Among the various magnetic nanoparticles, spinel CoFe 2 O 4 and ZnFe 2 O 4 NPs have drawn recent interest with the aim to form stable nontoxic aqueous dispersion.…”

The Effect of Gelation on the Apparent Magnetism of ZnFe2O4 Sol-Gel Systems

“…Gelation "freezes" the translational degree of freedom and inhibits the hydrodynamic interaction, so that the apparent susceptibility and magnetization of gels are larger than those of sols. This shows that, just as for uniaxial ferrogels, the relative rotations between the moments and the network can be viewed as a magnetic degree of freedom (Bentivegna et al, 1999) for the ZnFe 2 O 4 gels. In other words, the sols have a translational degree of freedom that produces a hydrodynamic interaction, but gelation will freeze this translational degree of freedom and inhibit the hydrodynamic interaction, so the gel is more easily magnetized than a sol.…”

“…Gels sensitive to electric or magnetic fields are of interest as "smart" materials with unique potential applications (Tanaka et al, 1982;Qsada et al, 1992;Barsi et al, 1996;Suto et al, 2009;Leveis et al, 2010). Typically, magneto-sensitive gels consist of magnetic nanoparticles dispersed in an organic or inorganic matrix (Chaput et al, 1993;Li et al, 1999;Bentivegna et al, 1999;Casas et al, 2002;Bohlius et al, 2004;Galicia et al, 2011). As for magnetic sols, the novel magnetic features of such gels stems from the magnetic properties of the nanoparticles.…”

Phase matched magneto optical single mode rib waveguides based on geometrical adjustments

“…There are a number of candidate materials for the development of integrated magneto-optical waveguide devices such as isolators, modulators and circulators [1][2][3][4][5][6][7]. Amongst these are magnetic nanoparticles embedded in a silica gel [1].…”