Nanoparticles of Cobalt Ferrite: Influence of the Applied Field on the Organization of the Nanocrystals on a Substrate and on Their Magnetic Properties

Ferrite nanocrystals have been synthesized by use of functionalized surfactantsto give nanoparticles doped with 3.5 % in mass of cobalt ions. These nanoparticles can be aligned on a substrate on a very large scale when the particles are deposited in the presence of a magnetic field (see Figure). In the absence of an applied field, the particles self-assemble into large spheres.