Harouna-Mayer Sani Y, Tao Songsheng, Gong ZiZhou, V Zimmermann Martin, Koziej Dorota, Dippel Ann-Christin, Billinge Simon J L
Center for Hybrid Nanostructures (CHyN), Institute for Nanostructure and Solid-State Physics, University of Hamburg, Hamburg, Germany.
The Hamburg Center for Ultrafast Imaging, Hamburg, Germany.
IUCrJ. 2022 Jul 19;9(Pt 5):594-603. doi: 10.1107/S2052252522006674. eCollection 2022 Sep 1.
An approach is described for studying texture in nanostructured materials. The approach implements the real-space texture pair distribution function (PDF), txPDF, laid out by Gong & Billinge {(2018 ▸). arXiv:1805.10342 [cond-mat]}. It is demonstrated on a fiber-textured polycrystalline Pt thin film. The approach uses 3D PDF methods to reconstruct the orientation distribution function of the powder crystallites from a set of diffraction patterns, taken at different tilt angles of the substrate with respect to the incident beam, directly from the 3D PDF of the sample. A real-space equivalent of the reciprocal-space pole figure is defined in terms of interatomic vectors in the PDF and computed for various interatomic vectors in the Pt film. Furthermore, it is shown how a valid isotropic PDF may be obtained from a weighted average over the tilt series, including the measurement conditions for the best approximant to the isotropic PDF from a single exposure, which for the case of the fiber-textured film was in a nearly grazing incidence orientation of ∼10°. Finally, an open-source Python software package, , is described that may be used to help in studies of texture from 3D reciprocal-space data, and indeed for Fourier transforming and visualizing 3D PDF data in general.
本文描述了一种研究纳米结构材料织构的方法。该方法实现了龚和比林格（2018年▸）提出的实空间织构对分布函数（PDF），即txPDF（arXiv:1805.10342 [凝聚态物理]）。在纤维织构的多晶铂薄膜上进行了演示。该方法使用三维PDF方法，直接从样品的三维PDF中，根据在样品相对于入射束的不同倾斜角度下拍摄的一组衍射图样，重建粉末微晶的取向分布函数。根据PDF中的原子间矢量定义了倒易空间极图的实空间等效物，并针对铂薄膜中的各种原子间矢量进行了计算。此外，还展示了如何通过对倾斜系列进行加权平均来获得有效的各向同性PDF，包括从单次曝光中获得最接近各向同性PDF的最佳近似值的测量条件，对于纤维织构薄膜的情况，该条件是在约10°的近掠入射角方向。最后，描述了一个开源的Python软件包，它可用于帮助研究三维倒易空间数据中的织构，实际上也可用于一般的三维PDF数据的傅里叶变换和可视化。
