Synthesis and characterization of magnetic nanoparticles coated with a uniform silica shell

Magnetic nanoparticles with a proper surface coating are of outstanding interest for several applications, especially in the biomedical field. In this paper we present the synthesis of CoFe2O4 magnetic nanoparticles covered by a uniform silica shell. These particles were characterized by means of Transmission Electron Microscopy (TEM) and Small Angle Scattering of Polarized Neutrons (SANSPOL). This newly developed technique, taking advantage from the variation of magnetic contrast, allowed us to verify that the thickness of the silica shell can be accurately tailored through a very simple synthetic approach. (c) 2005 Elsevier B.V. All rights reserved.