Résumé
In the past few years we have witnessed the spectacular development of nanomaterials of spin crossover complexes of 3d4-3d7 transition metal ions, including thin films, nanoparticles, nanopatterns, and nanoscale assemblies. These developments were primarily motivated by fundamental questions concerning size redn. effects on the bistability properties. On the other hand, spin crossover nano-objects require new characterization techniques (scanning probe microscopy, micro-magnetometry, etc.), revealing unknown details of the SCO mechanism at the nanoscale and giving access also to properties, which were largely unexplored until now. We review these recent exptl. developments and discuss perspectives for societal applications as well.