The question that Poulsen and his team are trying to answer is what happens in metals when you apply tensile stress or strain, which is useful for future lighter and stronger materials for energy and aerospace applications.
Many physical and mechanical properties of these materials depend on their internal structure, which is organised into grains of different sizes. The technique of dark field X-ray microscopy on ID03 maps in 3D orientations and stresses from 100 nanometres to 1 millimetre and allows zooming in and out in both direct and angular space.
The collaboration between Poulsen’s team and the ID03 staff, led by Carsten Detlefs, comes a long way. They started developing the technique of Dark X-ray microscopy several years ago and built the beamline from scratch. The significance of the novel technique became evident when Poulsen received an ERC Advanced Grant to contribute to its development.
This technique, which can only be carried out at the ESRF, allows studying materials at different scales. Unlike bright field microscopy, where the sample is seen on a bright background, dark field microscopy detects only light that is scattered by the sample, not from direct illumination. In case of dark-field x-ray microscopy, the signal originates from Bragg diffraction. This new technique is therefore ideal for crystalline materials like most metals, ceramics, rocks, ice, semiconductors, etc.
Read more here: Inauguration and first users for ID03 beamline (esrf.fr)
