Novel Way of Synthesizing Manganese Oxide Nanocrystals

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 4th, 2003.
For more information, please contact Stephen O'Brien.
(This work appeared in J. Am. Chem. Soc. 125, 10180-10181 (2003).)