Structure-property investigations of nanomaterials by Debye function analysis.

Complex nano-scaled materials of advanced functionalities are currently the central focus of several emerging fields in Nanoscience and Nanotechnology. Control at the molecular level of these objects, necessary for finely tuning the properties and for understanding the structure-property mechanisms, requires robust physico-chemical characterization methods. The Debye Function Analysis (DFA) is a powerful approach relying on Wide Angle Total Scattering X-ray (or Neutron) Techniques that, contrary to conventional Powder Diffraction methods, is able to quantitatively investigate the most relevant features of nanoparticles (NPs) and nanomaterials. The main objectives of this Thesis are: i) exploring experimental, modeling and computational aspects of DFA; ii) developing and applying the method to different classes of advanced nanomaterials; iii) assessing the DFA ability in extracting reliable quantitative information on the NPs structure and defectiveness, size and shape distribution, stoichiometry and phase composition, and surface effects, all within a unique coherent framework; iv) using the analytical, structural and microstructural characterization to interpret the material functional properties. Four classes of nanomaterials have been investigated. They include: iron oxide NPs and their important super-paramagnetic properties; biomimetic apatite NPs and their intriguing formation and growth mechanisms; two highly defective materials: the 1D Ru(CO)4 polymer, a potential metal nanowire precursor showing a structural disorder of paracrystalline nature, and the Ag/Cu nitropyrazolates, possessing a very complex defectiveness in which faulting and paracrystalline phenomena simultaneously occur.