Organization and magnetic properties of cigar-shaped ferrite nanocrystals

Abstract

Cigar-shaped maghemite (γ-Fe2O3) nanocrystals dispersed in aqueous solution are subjected to a magnetic field during the deposition (process) on graphite. The nanocrystals can thus be oriented along their long axis to form ribbons at a mesoscopic scale whereas without a field the nanocrystals remain randomly oriented on the substrate. The magnetic properties markedly depend on the organization of the nanocrystals within the mesostructures.