Materials characterization at the nano-scale was motivated by the desire to resolve the structural aspects and deformation behaviour at length scales relevant to those mechanisms that define the novel and unusual properties of nano-structured materials. A range of novel techniques had recently become accessible with the help of synchrotron X-ray beams that could be focused down to spot sizes of less than a few microns on the sample. The unique combination of tunability (energy selection), parallelism and brightness of synchrotron X-ray beams allowed their use for high resolution diffraction (determination of crystal structure and transformations, analysis of dislocation sub-structures, orientation and texture analysis, strain mapping); small angle X-ray scattering (analysis of nano-scale voids and defects; orientation analysis) and imaging (radiography and tomography). After a brief review of the state-of-the-art capabilities for monochromatic and white-beam synchrotron diffraction, the usefulness of these techniques in bridging the gap between experiment and modelling was considered. It was surmised how experiments might be configured in order to provide information which was relevant to the validation of, and improvement in, modelling approaches and how the results of various simulations could be post-processed so as to improve the possibility of (more or less) direct comparison with experiments. Using the example of some recent experiments, it was considered how such experimental results could be interpreted in conjunction with numerical deformation models; especially those incorporating dislocation effects. That is, for example, finite-element based pseudo-continuum strain gradient formulations, and discrete dislocation simulations. Post-processing of finite-element and discrete dislocation simulations was used to illustrate the kind of information that could be extracted from comparisons between modelling and experimental data.

Probing Deformation Substructure by Synchrotron X-ray Diffraction and Dislocation Dynamics Modelling. A.M.Korsunsky, F.Hofmann, X.Song, S.Eve, S.P.Collins: Journal of Nanoscience and Nanotechnology, 2010, 10[9], 5935-50