Neutron scattering on magnetic nano-objects

In 3 dimensions, it is possible to identify a wide range of systems such as (i) nanoparticles in solutions forming ferrofluids, (ii) percolating phases as found in manganites for example, (iii) magnetic domains or domain walls in crystals, (iv) long range helical structures as found in MnSi or BiFeO3 for example. These objects are ideally studied using Small Angle Neutron Scattering (SANS) which enable measuring either the shape of individual objects (form factor) or their long range organization (structure factor). In 2 dimensions, nanometer size objects organized on surfaces. These objects can be either produced by lithography techniques or by self-organization processes. The scattering technique which can be used is either SANS or Grazing Incidence SANS. In 1 dimension, thin films produced by physical means such as vacuum deposition (sputtering, evaporation, laser ablation ...): metal thin films, oxide thin films, magnetic semi-conductors. These systems are most ideally studied by polarized neutron reflectivity. This is the object of a dedicated chapter.