Structural phase transition and ferromagnetism in monodisperse 3nm FePt particles

The preparation, structural phase transition and magnetic characterizations of heat-treated monodisperse FePt nanoparticles of 3nm size are described. The results have shown that the transformed 3 nm nanoparticles have a magnetic anisotropy constant that is smaller than those for the bigger particles and the fully ordered [L1.sub.0] bulk phase.