Department of Materials, University of Oxford, Parks Road, Oxford OX13PH, UK.
Ultramicroscopy. 2011 Jun;111(7):877-86. doi: 10.1016/j.ultramic.2010.10.012. Epub 2010 Oct 27.
Scanning confocal electron microscopy (SCEM) offers a mechanism for three-dimensional imaging of materials, which makes use of the reduced depth of field in an aberration-corrected transmission electron microscope. The simplest configuration of SCEM is the bright-field mode. In this paper we present experimental data and simulations showing the form of bright-field SCEM images. We show that the depth dependence of the three-dimensional image can be explained in terms of two-dimensional images formed in the detector plane. For a crystalline sample, this so-called probe image is shown to be similar to a conventional diffraction pattern. Experimental results and simulations show how the diffracted probes in this image are elongated in thicker crystals and the use of this elongation to estimate sample thickness is explored.
扫描共聚焦电子显微镜（SCEM）提供了一种对材料进行三维成像的机制，该机制利用了经过像差校正的透射电子显微镜中较小的景深。SCEM 的最简单配置是明场模式。在本文中，我们展示了实验数据和模拟结果，这些结果显示了明场 SCEM 图像的形式。我们表明，三维图像的深度依赖性可以根据在探测器平面上形成的二维图像来解释。对于晶体样品，这种所谓的探针图像被证明类似于传统的衍射图案。实验结果和模拟结果显示了在这种图像中，衍射探针在较厚的晶体中如何被拉长，以及如何利用这种伸长来估计样品厚度。
