%0 Journal Article
%A Gonzalez Fernandez, M. A.
%A Torres, T.
%A Andrés Vergés, M.
%A Costo, R.
%A Presa Muñoz De Toro, Patricia Marcela De La
%A Serna, C. J.
%A Morales, M. P.
%A Marquina, C.
%A Ibarra, M. R.
%A Goya, G. F.
%T Magnetic Nanoparticles for Power Absorption: optimizing size, shape and magnetic properties.
%D 2009
%@ 0022-4596
%U https://hdl.handle.net/20.500.14352/42780
%X We present a Study on the magnetic properties of naked and silica-coated Fe₃O₄nanoparticles with sizes between 5 and 110 nm. Their efficiency as heating agents was assessed through specific power absorption (SPA) measurements as a function of particle size and shape. The results show a strong dependence of the SPA with the particle size, with a maximum around 30 nm, as expected for a Neel relaxation mechanism in single-domain particles. The SiO₂shell thickness was found to play an important role in the SPA mechanism by hindering the heat Outflow, thus decreasing the heating efficiency. It is concluded that a compromise between good heating efficiency and surface functionality for biomedical purposes can be attained by making the SiO₂functional coating as thin as possible.
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