Laser pyrolysis preparation of SiO2-coated magnetic nanoparticles for biomedical applications

The encapsulation of magnetic particles into silica has been achieved efficiently in a single and continuous process by laser-induced pyrolysis of ferrocene and TEOS aerosols. This process results in rather homogeneous iron/magnetite particles smaller than 10 nm in diameter surrounded by a SiO2 coating of about 20 nm. Interactions between the metal core and the passivation layer dominates the coercivity at low temperature in these systems. (c) 2004 Elsevier B.V. All rights reserved.