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

Optical and magneto-optical properties of maghemite superparamagnetic parti cles dispersed (f = 0.28 vol% gamma-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. Th e spectral dispersion of Faraday effects in our textured samples is analyze d taking into account the in-plane optical anisotropy. Such a composite mat erial is a promising candidate for future magneto-optical applications. (C) 1999 American Institute of Physics. [S0021-8979(99)00404-1].