Rudolph Martin, Motylenko Mykhaylo, Rafaja David
Institute of Materials Science, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 5, D-09599 Freiberg, Germany.
IUCrJ. 2019 Jan 1;6(Pt 1):116-127. doi: 10.1107/S2052252518015786.
The defect structure of γ-AlO derived from boehmite was investigated using a combination of selected-area electron diffraction (SAED) and powder X-ray diffraction (XRD). Both methods confirmed a strong dependence of the diffraction line broadening on the diffraction indices known from literature. The analysis of the SAED patterns revealed that the dominant structure defects in the spinel-type γ-AlO are antiphase boundaries located on the lattice planes , which produce the sublattice shifts . Quantitative information about the defect structure of γ-AlO was obtained from the powder XRD patterns. This includes mainly the size of γ-AlO crystallites and the density of planar defects. The correlation between the density of the planar defects and the presence of structural vacancies, which maintain the stoichiometry of the spinel-type γ-AlO, is discussed. A computer routine running on a fast graphical processing unit was written for simulation of the XRD patterns. This routine calculates the atomic positions for a given kind and density of planar defect, and simulates the diffracted intensities with the aid of the Debye scattering equation.
利用选区电子衍射（SAED）和粉末X射线衍射（XRD）相结合的方法，对由勃姆石衍生的γ-AlO的缺陷结构进行了研究。两种方法均证实衍射线展宽强烈依赖于文献中已知的衍射指数。SAED图谱分析表明，尖晶石型γ-AlO中的主要结构缺陷是位于晶格平面上的反相边界，其会产生亚晶格位移。从粉末XRD图谱中获得了有关γ-AlO缺陷结构的定量信息。这主要包括γ-AlO微晶的尺寸和平面缺陷的密度。讨论了平面缺陷密度与维持尖晶石型γ-AlO化学计量的结构空位的存在之间的相关性。编写了一个在快速图形处理单元上运行的计算机程序，用于模拟XRD图谱。该程序计算给定种类和密度的平面缺陷的原子位置，并借助德拜散射方程模拟衍射强度。
