Caratterizzazione spettroscopica di nanomateriali

The aim of this thesis has been the spectroscopic characterization of different kinds of nanomaterials. The interest in these materials is driven by the fact that approaching nanometer dimensions peculiar and different electrical, optical and magnetic properties with respect to those observed in the bulk phase can be observed, as the emergence of quantum effects. Therefore, nanomaterials represent promising objects both for the study of fundamental science and for new interesting applications in many technological fields. Three different magnetic nanomaterials (a single molecule magnet, a molecular chain and magnetic nanoparticles) and a spin crossover complex have been studied. The study of these materials allowed to characterize different behaviors associated with their different dimensions and structure, starting from the single iron ion, passing to a cluster of interacting ions, that is the base of a single molecule magnet, to end with an ensemble of hundreds of ions, that constitutes a magnetic nanoparticle. In this size range the molecular approach allows to understand the properties of systems starting from the single molecule and therefore to follow the evolution of the properties of the system towards macroscopic dimensions. In order to characterize these nanomaterials and face some of the open problems regarding them and their use in the proposed applications, state-of-the-art configurations of Mössbauer spectroscopy or electron paramagnetic resonance (EPR) spectroscopy were used.