Determination of crystal phase from an electron backscatter diffraction pattern
Determination of crystal phase from an electron backscatter diffraction pattern
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DOI：
10.1107/s0021889809001654
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发表时间：
2009-04
影响因子：
6.1
通讯作者：
D. Dingley;S. Wright
中科院分区：
文献类型：
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作者：
D. Dingley;S. Wright
电子背散射衍射（EBSD）是一种基于扫描电子显微镜的技术，主要用于确定和绘制晶体取向。这项工作描述了EBSD技术的适应性，使其成为测定晶体相位的潜在工具。该过程可分为三个步骤：(1)从单个EBSD图中提取三斜晶胞，(2)从三斜晶胞的检查中识别晶体对称性，(3)确定晶格参数。通过在图案中找到通过两个带轴的带（包括连接两个带的带）来确定三斜细胞。在此基础上，构建了三维三棱形单元胞。EBSD模式是根据由此形成的三斜细胞和计算的晶体取向来索引的。由于晶体实际具有的对称性，图案标引导致了独立的多取向。通过研究这些多取向之间的关系，建立了晶体体系。通过将模拟的菊池带与图形进行比较，可以确定晶格参数。以钛六方相的EBSD图为例，给出了该方法的具体方法。
Electron backscatter diffraction (EBSD) is a scanning electron microscope-based technique principally used for the determination and mapping of crystal orientation. This work describes an adaptation of the EBSD technique into a potential tool for crystal phase determination. The process can be distilled into three steps: (1) extracting a triclinic cell from a single EBSD pattern, (2) identifying the crystal symmetry from an examination of the triclinic cell, and (3) determining the lattice parameters. The triclinic cell is determined by finding the bands passing through two zone axes in the pattern including a band connecting the two. A three-dimensional triclinic unit cell is constructed based on the identified bands. The EBSD pattern is indexed in terms of the triclinic cell thus formed and the crystal orientation calculated. The pattern indexing results in independent multiple orientations due to the symmetry the crystal actually possesses. By examining the relationships between these multiple orientations, the crystal system is established. By comparing simulated Kikuchi bands with the pattern the lattice parameters can be determined. Details of the method are given for a test case of EBSD patterns obtained from the hexagonal phase of titanium.