UXS – From the atomic structure to the nanocrystal morphology: a Unified X-ray Scattering approach for characterizing nanomaterials
European Union e Aarhus Institute of Advanced Studies (Aarhus University), Marie Skłodowska-Curie cofund grant (EU-FP7 program, Grant Agreement No. 609033).
SHORT DESCRIPTION AND USEFUL INFO:
Peaks shape and broadening in the diffraction profile of nanocrystals (NCs) result from the coexistence of different effects such as the reduced coherent domains and peculiar (often anisotropic) morphologies, surface-induced lattice strains and other type of structural or compositional defects (i.e. point or planar defects, such as dislocations, twin boundaries or stacking faults). Therefore, the information in the powder diffraction pattern is smeared out and limited, while the complexity of the structure is highly increased. Not being restricted to ideally periodic and ordered materials, the Debye Scattering Equation (DSE)-based approach treats Bragg and diffuse scattering on an equal basis therefore modeling the total scattering pattern of nanocrystals. Since the DSE computation starts from real space atomistic models, the structural and microstructural information are considered within a unified approach. However, when dealing with very small and highly defective materials, disentangling size and shape from defects-induced effects on peak shape and broadening is not a trivial task and deem it necessary resorting to complementary, “structure insensitive”, techniques, such as Small Angle X-ray Scattering (SAXS). The project comes from the collaboration between iNANO (Aarhus University, DK) and To.Sca.Lab (University of Insubria and IC-CNR, Como, IT) and focuses on a Unified Small and Wide Angle X-ray Total Scattering approach for nanocrystal characterization, along with the definition and implementation of new experimental, theoretical and analytical protocols for a full quantitative characterization of nanomaterials featuring different structure, defectiveness and morphology.
Further information available at : http://aias.au.dk/aias-fellows/federica-bertolotti/
Dr. Federica Bertolotti
Aarhus Institute of Advanced Studies (Aarhus University) and To.Sca.Lab
Høegh-Guldbergs Gade 6B, building 1630 (r201), 8000 Aarhus C (DK)