Ayer R
Corporate Research Laboratories, Exxon Research and Engineering Company, Annandale, New Jersey 08801.
J Electron Microsc Tech. 1989 Sep;13(1):16-26. doi: 10.1002/jemt.1060130105.
The ability to obtain diffraction patterns with a large angular view has significantly enhanced the ease and potential of electron diffraction studies in the determination of unit cells and identification of submicron phases. Convergent beam electron diffraction (CBED) provides a two-dimensional projection of the three-dimensional reciprocal lattice and can be utilized to reconstruct the unit cell dimensions. In particular, the spacing of the reciprocal lattice layers parallel to the electron beam and the location and distribution of the reflections in the first and higher order Laue zones with respect to the zero layer provide information which cannot be obtained from the zero layer pattern alone. This additional information permits the identification of crystal structures of phases under investigation with previously established ones or the determination of a new structure, if previously unknown. The article describes the principles of the analysis and illustrates the application of the methods with examples from commercial material systems.
能够获得大角度视图的衍射图样，极大地提高了电子衍射研究在确定晶胞和识别亚微米相方面的便利性和潜力。会聚束电子衍射（CBED）提供了三维倒易晶格的二维投影，可用于重建晶胞尺寸。特别是，平行于电子束的倒易晶格层间距以及一阶和高阶劳厄区中反射相对于零层的位置和分布，提供了仅从零层图样无法获得的信息。这些额外信息允许将所研究相的晶体结构与先前已确定的结构进行比对识别，或者在先前未知的情况下确定新结构。本文描述了分析原理，并通过商业材料系统的实例说明了这些方法的应用。
