Mesoscopic structures maghemite nanocrystals: Fabrication, magnetic properties, and uses

Mesoscopic structures made of maghemite (gamma-Fe2O3) nanocrystals with different coatings and shapes are described. They are controlled by a combination of van der Waals and magnetic dipolar interactions and their shapes are responsible for the collective magnetic response of the nanocrystals. It is shown that spherical gamma-Fe2O3 nanocrystals can be used as a mask to reproduce the mesoscopic structure on a silicon wafer.