IMX Talks - X-ray scattering and imaging for hierarchical materials

Microscopy in scanning mode allows to image different contrasts from the sample, by probing not only absorption and phase contrast of the sample but for example a full X-ray fluorescence spectrum or a 2D scattering pattern. Small- and wide-angle X-ray scattering (SAXS/WAXS) imaging is in particular valuable for heterogeneous samples, in which structural elements in the nano- or Ångström-scale change over macroscopic length scales, thus several millimeters or centimeters. The scattering patterns provide statistical information in each scan point, thus this method is complementary to high-resolution imaging techniques. The information extracted from each scattering pattern can be used to create images with different contrast, such as density of nano-scale features or orientation of nanostructures. These methods can also be combined with computed tomography to study the inside of three-dimensional samples, as shown on the example of bone in Figure 1. A range of applications will be shown from biological tissues to various soft-matter systems. Linking for example the structural layers induced by the injection-molding process in semi-crystalline polymers used in food packaging industry to their anisotropic mechanical properties. Combining SAXS imaging with microfluidics extends the method from imaging solid sample to mapping of nanostructures in flow.
Bio: Marianne Liebi is Adjunct Associate Professor in Materials Science in the Department of Physics at the Chalmers University of Technology, and Scientific Group Leader in the Center for X-ray Analytics at Empa, St.Gallen since August 2020. She started her own research group in 2017 as Assistant Professor at the Chalmers University of Technology and became Docent in Physics in spring 2020. The focus of her research is in the development of advanced X-ray imaging techniques and their application towards materials with hierarchical structures. Her main expertise is small-angle X-ray scattering (SAXS) imaging in 2D and 3D, but include other imaging modalities such as ptychographic nanotomography, X-ray fluorescence or phase contrast tomography. With a background in food science, she started using small-angle neutron scattering (SANS) for the characterization of soft-matter, namely of magnetic alignable self-assembly structures during her PhD, received from ETH Zurich, Switzerland in 2013. As a Post Doc in the coherent X-ray scattering group at the Swiss Light Source (SLS), she worked from 2013-2016 on method development in SAXS imaging, and from 2016-2017  at the NanoMAX beamline at the MAX IV Laboratory, in Lund Sweden.