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.