The
magnetic, structural and transport properties of manganese oxides
have fascinated scientists for many years; these manganese oxides
find applications in catalysis and battery technologies. MnO is
a model system for the theoretical study of electronic and magnetic
properties of rocksalt oxides, and recent studies have suggested
ferromagnetic behavior in MnO at the nanoscale (though MnO is
antiferromagnetic in the bulk). One interesting question here
is: what is the bulk limit for antiferromagnetic behavior? Professor
Stephen O?Brien and collaborators the Columbia University
MRSEC have synthesized highly crystalline, monodisperse nanocrystals
of manganese oxides without size selection, using a process illustrated
in the accompanying figure. Nanocrystals with diameters between
6 to 20 nm can prepared that are capped with oleic acid and dispersible
in non-polar solvents. Nanocrystal superlattice formation has
been observed.

Schematic of the synthesis of manganese oxide nanocrystals
Posted
March 4, 2003.
For more information, please contact Stephen
O'Brien.
(This work appeared in J. Am. Chem. Soc. 125, 10180-10181 (2003).)