Advanced Characterization of Nanocrystalline Materials by Synchrotron Radiation X-ray Diffraction

Synchrotron Radiation (SR) is one of the most powerful and versatile tools in the study nanomaterials, supporting a variety of analytical techniques. Among the possible spectroscopies, X-ray Diffraction (XRD) is especially suited to investigate materials at the nanoscale. However, to benefit of the full potential of SR XRD, a complete control of the diffracted signal is necessary, including the optics and general setâ up of the beamline, which contribute to the Instrumental Profile Function (IPF). Exploring and characterizing the optical components for powder diffraction beamlines is the bottom line of the present Thesis, with the purpose of properly calibrating and adjusting all components in order to deliver the beam under the best possible conditions. Main benefits of this novel approach appear in the study of relatively large crystalline domains, toward the upper limit of the nanoscale (â hundreds of nm), a critical range between nano- and micro-crystalline, where the IPF is the main feature appearing in the experimental data. Thanks to this investigation it was possible to develop solutions and tools to improve knowledge and enhance the capability of handling the IPF along the life-cycle of a powder diffraction experiment. This result was achieved by studying and characterizing a new possible reference material for Line Profile Analysis (of size and strain effects), and by developing an original simulation/modelling software, based on rayâ tracing algorithms, capable to predict and analyse the instrumental behaviour of a beamline. As such the results of this work, and in a more general sense the emerging paradigm, will be of interest to many other beamlines currently employed for X-ray spectroscopies.