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MM: Fachverband Metall- und Materialphysik
MM 65: Nanomaterials - II
MM 65.1: Vortrag
Donnerstag, 19. März 2020, 17:30–17:45, IFW D
3D X-ray Diffraction Microscopy (3DXRD) using high resolution X-ray nanodiffraction — •Hergen Stieglitz1, Johan Hektor2, Anton Davydok1, Christina Krywka1, and Martin Müller1 — 1Helmholtz-Zentrum Geesthacht, Geesthacht, Germany — 2DESY, Hamburg, Germany
The existing technology called 3DXRD is a well-established technique to map the grain structure of polycrystalline systems (e.g. metals). This technology is based on reconstruction algorithms which trace the positions of multiple Bragg-Peaks as a function of the rotation angle during sample rotation. These algorithms rely on that the diffraction spots do not overlap. Therefore there is a limit on the maximum number of grains, or equivalently, the smallest grain size that can be mapped.
The newly implemented nano grain mapping experiment at the beamline P03 (PETRA III) is based on scanning 3DXRD and utilizes a nano-focused X-ray synchrotron beam to examine very fine-grained systems. With respect to the small beam size of about 250 nm cross section, the precise positioning of the sample becomes more important to secure a constant gauge volume. Otherwise some grains may be outside the gauge volume in some scans, therefore they cannot be traced and produce mistakes while reconstructing.
To meet this challenge a stable and wobble-free rotation stage is in operation to ensure a constant gauge volume. A laser interferometer based feedback loop compensates the runout of the sample during rotation. Results of the very first experiments will be shown.