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Synthesis of Monodisperse Iron Oxide Nanoparticles Iron oxide particles constitute a diverse class of materials displaying
a range of optical, magnetic and catalytic properties could harnessed
in a variety of applications. A new synthesis procedure was developed
by Professor Stephen O'Brien, in collaboration with Dr. Chris
Murray of the IBM T. J. Watson Research Center, and MRSEC/IBM
bridging postdoctoral scientist Dr. Franz Redl. This chemical
synthesis is based on the decomposition of Fe(CO)5
to make very monodisperse ligand capped particles. Ferrimagnetic
iron oxides (such as the 12 nm diameter gamma-Fe2O3
shown in the picture on the right) and mixed metal oxides have
applications in magnetic storage, high frequency transformers
and RF and microwave components. The semiconducting properties
of alpha-Fe2O3 suggest strong potential
for this material in photocatalysis while the half metallic behavior
of Fe3O4 has generated considerable interest
in spin polarized electronics. In addition to electronic applications
the stability and bio-compatibiliy of the iron oxides are making
them leading candidates for drug delivery, diagnostic and medical
imaging applications. This TEM (transmission electron micrograph)
shows ordered assembly that is a consequence of the monodispersity
in nanoparticle size. Similar work has been done recently in South
Korea by Prof. Hyeon, who will now collaborate with the Columbia
MRSEC on new synthetic procedures.
Posted February 13, 2002. |
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