Monodispersed and highly ordered L10 FePt nanoparticles prepared in the gas phase

We report the direct preparation of monodispersed L10 phase FePt nanoparticles by controlled nucleation and growth using a gas phase aggregation source. These FePt nanoparticles became ordered during their growth in an argon gas flow. They are octahedron faceted with an average size of 5.8nm and a standard size distribution of 11%, as illustrated by transmission electron microscope. Magnetic measurements show that these FePt nanoparticles have coercivities of 8.25kOe at room temperature and 26.5kOe at 50K. This technique provides a novel approach for fabricating nanomaterials with controllable phase and shape in general.