Microstructure and magnetic properties of cobalt nanocrystals

Cobalt nanocrystals are synthesized by rapid pyrolysis of cobalt carbonyl in an inert atmosphere. The size distribution and particle shape of the crystals are controlled by varying the surfactant, its concentration and the reaction temperature. The particles are observed to contain abundant planar defects and their self-assemblies are found to be strongly dependent on their magnetic states. Magnetic order in nanocrystal chains are studied by electron holography.