  We investigated effects of annealing time on structural and magnetic
properties of the L10-FePt nanoparticles synthesized by the SiO2-nanoreacter
method. The magnetization and powder X-ray diffraction studies revealed that
the annealing at 900 oC for 9 hr could convert all of the fcc-nanoparticles to
the well-crystallized L10 structure with a large coercivity while keeping their
particle size. Such monodisperse and highly crystalline L10-FePt nanoparticles
are a promising material for the realization of ultra-high density recording.
