Bird D M
School of Physics, University of Bath, England.
J Electron Microsc Tech. 1989 Oct;13(2):77-97. doi: 10.1002/jemt.1060130202.
The theory of high-energy electron diffraction is reviewed, with an emphasis on methods that help most in understanding the form of zone axis convergent-beam patterns. A Bloch wave description is used throughout the paper, and the theory is formulated in real space, leading to general expressions for both zero-layer and higher-order Laue zone (HOLZ) diffraction amplitudes. HOLZ diffraction is discussed in detail, and it is shown that first-order perturbation theory is usually applicable and provides a clear picture of the diffraction. The computation of diffracted intensities is discussed with reference to the many-beam equations. Diffraction at the [0001] axis in 1T-VSe2 is analysed both to illustrate the theory and to provide an example of the special effects that occur at well defined string zone axes.
本文回顾了高能电子衍射理论，重点介绍了对理解晶带轴会聚束图样形式最有帮助的方法。整篇论文采用布洛赫波描述，理论在实空间中建立，得出了零层和高阶劳厄区（HOLZ）衍射振幅的一般表达式。详细讨论了HOLZ衍射，结果表明一阶微扰理论通常适用，并能清晰地呈现衍射情况。结合多束方程讨论了衍射强度的计算。分析了1T-VSe₂中[0001]轴的衍射，以阐释该理论，并给出在明确的弦晶带轴处出现的特殊效应的示例。
