Monodisperse FePt nanoparticles and ferromagnetic FePt nanocrystal superlattices
Synthesis of monodisperse iron-platinum (FePt) nanoparticles by reduction of platinum acetylacetonate and decomposition of iron pentacarbonyl in the presence of oleic acid and oleyl amine stabilizers is reported. The FePt particle composition is readily controlled, and the size is tunable from 3- to 10-nanometer diameter with a standard deviation of less than 5%. These nanoparticles self-assemble into three-dimensional superlattices. Thermal annealing converts the internal particle structure from a chemically disordered face-centered cubic phase to the chemically ordered face-centered tetragonal phase and transforms the nanoparticle superlattices into ferromagnetic nanocrystal assemblies. These assemblies are chemically and mechanically robust and can support high-density magnetization reversal transitions.
Sun
S
IBM T. J. Watson Research Center, Yorktown Heights, NY 10598, USA. IBM Almaden Research Center, 650 Harry Road, San Jose, CA 95120, USA.
Murray
CB
Weller
D
Folks
L
Moser
A