Electronic and Magnetic Properties of Monodispersed FePt Nanoparticles

Mössbauer spectroscopy of FePt nanoparticles demonstrates the presence of two iron phases: one consistent with a bulk FePt alloy, the other due to a polarized phase (Fen+), in agreement with a negative polarization on the oleate moiety. FePt metallic nanoparticles (see Figure for the TEM image of a Fe50Pt50 phase) are important materials for new sensors and magnetic recording devices with high information densities.