Morniroli J P, Houdellier F, Roucau C, Puiggalí J, Gestí S, Redjaïmia A
Laboratoire de Métallurgie Physique et Génie des Matériaux, UMR CNRS 8517, USTL & ENSCL, Cité Scientifique, 59655 Villeneuve d'Ascq, France.
Ultramicroscopy. 2008 Jan;108(2):100-15. doi: 10.1016/j.ultramic.2007.03.006. Epub 2007 Mar 27.
By combining the large-angle convergent-beam electron diffraction (LACBED) configuration together with a microscope equipped with a C(s) corrector it is possible to obtain good quality spot patterns in image mode and not in diffraction mode as it is usually the case. These patterns have two main advantages with respect to the conventional selected-area electron diffraction (SAED) or microdiffraction patterns. They display a much larger number of reflections and the diffracted intensity is the integrated intensity. These patterns have strong similarities with the electron precession patterns and they can be used for various applications like the identification of the possible space groups of a crystal from observations of the Laue zones or the ab-initio structure identifications. Since this is a defocused method, another important application concerns the analysis of electron beam-sensitive materials. Successful applications to polymers are given in the present paper to prove the validity of this method with regards to these materials.
通过将大角度会聚束电子衍射（LACBED）配置与配备有C（s）校正器的显微镜相结合，能够在图像模式而非通常情况下的衍射模式下获得高质量的斑点图案。相对于传统的选区电子衍射（SAED）或微衍射图案，这些图案具有两个主要优点。它们显示出更多数量的反射，并且衍射强度是积分强度。这些图案与电子进动图案有很强的相似性，可用于各种应用，如通过观察劳厄区确定晶体可能的空间群或从头结构鉴定。由于这是一种离焦方法，另一个重要应用涉及对电子束敏感材料的分析。本文给出了在聚合物上的成功应用，以证明该方法对于这些材料的有效性。
