![]() ![]() Ce travail de thèse est une contribution au développement d'une technique de microscopie par diffraction des rayons X, appelée "Differential Aperture X-ray Microscopy", (DAXM, permettant la caractérisation 3D et non-destructive de la microstructure de matériaux cristallins et des contraintes internes présentes dans le matériau. La caractérisation des contraintes internes présentes dans les matériaux de structure ou fonctionnels est primordiale pour une optimisation de leurs propriétés et de leur tenue en service. The formation of micro SrZrO3 inclusions in LSCF layer is then indubitably identified, as well as in the CGO/YSZ interface. The method can provide a more representative information and may offer some insights on the reactivity distribution along the interfaces. The present approach offers a larger field of view in comparison to electron microscopy techniques. The cathode was deposited on a dense YSZ electrolyte substrate spaced by a thin Gadolinium doped Ceria Oxide (CGO) barrier layer in between LSCF and YSZ to limit the reactivity. In order to address the reactivity issues locally in the micrometre scale range, 2D and 3D X-ray μ-diffraction and μ-fluorescence analysis have been performed on a pristine LSCF cathode layer. However, its chemical reactivity with the Yttria-stabilized Zirconia (YSZ) electrolyte still remains one of the main challenges, which demands a comprehension in the μm and sub-μm range. Especially in the Solid Oxide Fuel Cell (SOFC) technology, this compound has receiving great attention as a cathode material. The development and application of an original geometrical approach to analyze the SOFC Laue data allowed the authors to resolve grains with sizes of about 3 µm and to identify their individual Laue patterns by indexing those Laue patterns, the crystalline phases and orientations of most of the grains identified through the geometrical approach could be resolved.ĭue to the mixed ionic electronic conductive properties of the Lanthanum Strontium Cobalt Ferrite (LSCF) La0.6Sr0.4Co0.2Fe0.8O3−δ compound, it is of great scientific and technological interest. The indexing procedure has been successfully applied for the analysis of the germanium Laue data, and the depth-resolved two-dimensional cartographies of the full deviatoric strain tensor components were obtained. The SOFC and germanium Laue diffraction pattern analyses are compared and discussed. In order to calibrate the Laue data and to test the technique's sensitivity limits, a monocrystalline germanium sample of about 8 × 4 µm in cross-section size has also been studied through µ-LT. For this purpose, a multiphase solid oxide fuel cell (SOFC) electrode composite made of yttria-stabilized zirconia and nickel oxide phases, with grains of about a few micrometres in size, has been analyzed. Published under an exclusive license by AIP Publishing.The relevance of micro Laue diffraction tomography (µ-LT) to investigate heterogeneous polycrystalline materials has been studied. Euler, Nova Methodus Motum Corporum Rigidorum Degerminandi ( Euler Archive, 1776), p. Koepke, in International Conference on Machine Learning ( PMLR, 2015), pp. Hanson, Solving Least Squares Problems ( SIAM, 1995). Rheinboldt, Iterative Solution of Nonlinear Equations in Several Variables ( SIAM, 2000). Ice, Strain and Dislocation Gradients from Diffraction: Spatially-Resolved Local Structure and Defects ( World Scientific, 2014). Mertz, Transformations in Optics ( Wiley, New York, 1965). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |