Magnetic disorder in nanostructured materials

This chapter deals with the effect of magnetic disorder on macroscopic magnetic properties of nanoparticles. Due to their rich crystal chemistry, nanoparticles of spinel ferrites will be taken as a model system. After a short overview on magnetism at the nanoscale, a physical description of magnetic disorder and experimental investigation will be given. Then several examples on the effect of magnetic disorder and more in general on the spin structure on macroscopic magnetic structure will be discussed. In addition, particular attention will be given on the possibility to have a “molecular control” of magnetic disorder, discussing the role of molecules bonded on particles surface. Finally, new perspective in the investigation of magnetic disorder at the nanoscale will be discussed.